AM35x-OMAP35x-PSP 03.00.00.04 DataSheet

Content is no longer maintained and is being kept for reference only!

Important
AM/DM37x support is included for internal development only.

Document License

This work is licensed under the Creative Commons Attribution-Share Alike 3.0 United States License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/us/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA.

Read This First

Content is no longer maintained and is being kept for reference only!

About This Manual

This document provides an overview and performance data for each of the device drivers which are part of the Linux PSP package supporting AM3517,OMAP35x and AM/DM37x Socs. Note that only a subset of these platforms may have actually been tested and verified in the package you are using. Please refer to the release notes provided with the package for information on which platforms have actually been verified.

If You Need Assistance

For further information or to report any problems, contact http://community.ti.com/ or http://support.ti.com/

Trademarks

OMAP^TM is trademark of Texas Instruments Incorporated. All other trademarks are the property of the respective owner.

PSP Linux Drivers

This section provides brief overview of the device drivers supported in the Linux PSP release based on Linux OMAP git tree at http://git.kernel.org/?p=linux/kernel/git/tmlind/linux-omap-2.6.git

Note: The constraints may vary across product releases. Please refer to the Release Notes accompanying the release for an updated list of constraints.

OMAP Linux PSP details

1. Supports for OMAP35x,AM/DM37x Socs (on OMAP3EVM Rev.G) and AM3517 Soc on AM3517EVM
2. Built with Linux kernel version 2.6.32/PM.
3. Compiled with code sourcery tool chain version arm-2009-q1-203.
4. Supports U-Boot version 2009.11
5. Supports boot from MMC and NAND flash.
6. Ships with sample root file system, ramdisk, pre-built u-boot, uImage binaries, sample applications and documentation.

Boot modes supported

Green colored box in the table below means that the particular boot mode is supported on the device.

Note: These are supported boot modes in PSP software, the actual hardware may support many more boot modes than shown here. Please refer to hardware documentation for list of all supported boot modes.

OMAP SDK Supported Boot Modes

Boot Mode	OMAP35x	AM/DM37x	AM3517
NAND Flash	Yes	Yes	Yes
NOR Flash	No	No	No
MMC/SD	Yes	Yes	Yes

Device driver list

Device Driver List

Peripheral	Description	Linux driver type
Video Display	Video Display driver supporting LCD, DVI and TV out	V4L2 and Frame-buffer display driver
Ethernet	Transmit/receive network data. Supports Auto negotiation with 10/100 Mbps link speed	Netdev
Audio (McBSP)	Audio record and playback	ALSA SoC
MUSB Host	Supports MSC, HID and USB Audio/Video classes	USB HCD
MUSB Gadget	Supports File-storage and CDC/RNDIS	USB Gadget
MUSB OTG	Supports HNP/SRP	USB HCD
EHCI Host	MSC, HID(via a HS hub) and USB Audio/Video	USB HCD
NAND Flash	Flash storage system	MTD Character and Block
MMC/SD	Interface to MultiMedia Secure Digital cards	Block
Touch Screen	Enables the LCD to be used for touchscreen input	Input(event) driver
UART	Serial Communication Interface	Character
I2C	Inter-IC Communication	Character
SPI	Serial Peripheral Interface	Character
AM3517: CAN (HECC)	Transmit/receive data over CAN (HECC) peripheral using socketCAN interface	Netdev
AM3517: RTC (S35390A)	Real Time Clock over I2C1	RTC Framework
AM3517: Capture	Capture driver supporting BT656 mode	V4L2 Sub-Device framework based
OMAP35x,AM/DM37x: Video Capture	Capture driver supporting BT656 mode	V4L2-Int framework based
OMAP35x,AM/DM37x: Video Resizer	Character based Resizer Driver using V4L2-Buf layer for buffer management	Character driver using V4L2-Buf layer
OMAP35x,AM/DM37x: Keypad	Keypad driver for OMAP3EVM keypad	Input(event) driver
AM3517: Keypad	Keypad driver for TCA6416 IO expander based keypad	Input(event) driver
OMAP35x: Power Management	CPUIdle and dynamic tick	CPUIdle, dyntick

Drivers not supported

1. Power Management (cpufreq, cpuidle) on AM3517

Driver DMA usage

OMAP35x,AM/DM37x,AM3517 peripheral driver DMA usage

Driver	DMA usage
Audio (McBSP)	sDMA
Ethernet	Internal DMA(AM3517 only)
MUSB OTG	Internal DMA
USB EHCI	Internal DMA
NAND Flash	None
NOR Flash	None
DSS (V4L2/Fbdev Display)	Internal DMA
OMAP35x,AM/DM37x: ISP-Resizer	Internal DMA
AM3517: VPFE Capture	Internal DMA
OMAP35x,AM/DM37x: ISP-Camera	Internal DMA
SPI	sDMA
MMC/SD	sDMA
UART	None
I2C	None
AM3517: CAN (HECC)	None

ALSA SoC Audio Driver

This section provides details on ALSA SoC audio driver along with throughput and CPU load numbers.

Introduction

OMAP35x, AM/DM37x, AM3517 audio driver complies to the ALSA SoC framework.

ASoC framework provides better audio support for embedded SoC processors and portable audio codecs. It splits an embedded audio system into three components:

• Codec driver: The codec driver is generic and hardware independent code that configures the audio codec to provide audio capture and playback. It should contain no code that is specific to the target platform or machine.
• Platform driver: The platform driver can be divided into audio DMA and SoC Digital Audio Interface (DAI) configuration and control. The platform driver only targets the SoC CPU and must have no board specific code.
• Machine driver: The ASoC machine (or board) driver is the code that glues together the platform and codec drivers. It can contain codec and platform specific code. It registers the audio subsystem with the kernel as a platform device.

Following architecture diagram shows all the components and the interactions among them:

OMAP35x, AM/DM37x

AM3517

Driver Features

The driver supports the following features:

1. Supports AIC23 audio codec (on AM3517 only) and TPS65950 audio codec (on OMAP35x, AM/DM37x only) in ALSA SoC framework.
2. Multiple sample rates support (8KHz, 16KHz, 22.05KHz, 32KHz, 44.1KHz, 48KHz, 64KHz, 88.2KHz and 96KHz - AM3517; 8 KHz, 11.025 KHz, 12 KHz, 16 KHz, 22.05 KHz, 24 KHz, 32 KHz, 44.1 KHz and 48 KHz - OMAP35x) for both capture and playback.
3. Supports audio in stereo mode.
4. Supports simultaneous playback and record (full-duplex mode).
5. Start, stop, pause and resume feature.
6. Supports mixer interface for audio codecs.
7. Supports MMAP mode for both playback and capture.

Features Not Supported

1. OSS based applications, which use ALSA-OSS emulation layer, are not supported.
2. Formats such as TDM, Left and Right Justified are currently not supported.
3. Synthesizer and midi interfaces are not supported.

Constraints

1. By default, codec is configured in master mode and McBSP is used as slave. Testing of the audio sub-system is done in this configuration only.
2. Sampling frequencies for playback and capture streams should be same.
3. The audio driver does not allow opening the same stream (playback/capture) multiple times.

Supported System Calls

Refer ALSA project - the C library reference [1] for API calls.

Supported IOCTLs

NA

Performance and Benchmarks

The performance numbers were captured using the following:

• Word length in bits = 16
• Number of channels per sample = 2
• Power Management = Disabled

The performance numbers are same for on each of OMAP35x, AM/DM37x and AM3517 platforms. Commands used to capture the same are:

• aplay -c 2 -f S16_LE -r <<sample rate>> <<file_name>> :- Normal mode
• arecord -c 2 -f S16_LE -r <<sample rate>> <<file_name>> :- Normal mode
• aplay -c 2 -f S16_LE -r <<sample rate>> -M <<file_name>> :- MMAP mode
• arecord -c 2 -f S16_LE -r <<sample rate>> -M <<file_name>> :- MMAP mode

Audio Write Performance

Sampling Rate (in Hz)	CPU Load (in %)	CPU Load (in %)
	Normal Mode	MMAP Mode
8000	0	0
32000	0	0
44100	2	2
48000	2	2

Audio Read Performance

Sampling Rate (in Hz)	CPU Load (in %)	CPU Load (in %)
	Normal Mode	MMAP Mode
8000	0	0
32000	0	0
44100	2	2
48000	2	2

Ethernet Driver

This section provides details on Ethernet driver along with throughput and CPU load numbers.

Introduction

The Ethernet driver supports the Linux netdev interface.

Driver Features

The driver supports the following features:

1. 10/100 Mbps mode of operation.
2. Auto negotiation.
3. Support for multicast and broadcast frames.
4. Promiscuous mode of operation.
5. Full duplex and half duplex mode of operation.
6. Linux NAPI support

Features Not Supported

NA

Constraints

NA

Supported System Calls

Supports the socket() and related system calls in accordance with Linux architecture.

Performance and Benchmarks

OMAP35x,AM/DM37x,AM3517

Ethernet TCP - 100Mbps Mode Performance

TCP Window Size (in KBytes)	Bandwidth - OMAP35x (in Mbits/sec)	Bandwidth - AM3517 (in Mbits/sec)	Bandwidth - AM/DM37x (in Mbits/sec)
16	44.7	27	49.6
32	45.6	52	50.6
64	45.6	79	50.5
128	45.5	92	50.4

The performance numbers were captured using the iperf tool. Usage details are mentioned below:

• On the DUT iperf is invoked in the server mode  : "-s" - window size default of 212KB
• On PC Host invoke iperf in client mode  : "-c <server ip> -w <window size> -d -t60"
• The transfers are measured over a duration of 60Secs
• Cross cable is used to measure performance.
• Speed is set to 100Mbps
• Power Management disabled for measurement

Ethernet UDP - 100Mbps Mode Performance

UDP Buffer Size (in KBytes)	Bandwidth - OMAP35x (in Mbits/sec)	Bandwidth - AM3517 (in Mbits/sec)	Bandwidth - AM/DM37x (in Mbits/sec)
16	21.4	50	24.8
32	27.6	82	30.3
64	37.8	91	40.4
128	41.6	103	49.5

The performance numbers were captured using the iperf tool. Usage details are mentioned below:

• On the PC Host iperf is invoked in the server mode  : "-s -u -w 256k "
• On DUT invoke iperf in client mode  : "-c <server ip> -w <window size> -d -b 100M -t60"
• The transfers are measured over a duration of 60Secs
• Cross cable is used to measure performance.
• Speed is set to 100Mbps
• Power Management disabled for measurement

Video Display Driver

This section describes the Video Display driver architecture, driver features and performance numbers (throughput and CPU load).

Introduction

Video Display driver is based on two different frameworks, V4L2 and FBDEV.

Driver Features

1. Supports interfaces LCD, DVI and TV out
2. Supports TV display interface at NTSC and PAL resolutions
3. Supports YUV, UYVU, RGB565, RGB24P and RGB24 unpacked on video planes, in addition ARGB on video2 plane.
4. Supports RGB565, ARGB, RGBA, RGB24 packed and unpacked on graphics plane
5. Video planes controlled through V4L2 user interface whereas Graphic plane controlled through FBDEV user interface
6. Supports setting up of OSD window destinations (TV or LCD) through sysfs
7. Supports mmapped (driver allocated) and user buffer exchange mechanism in V4L2 driver and only mmapped (driver allocated) buffers in FBDEV driver
8. Supports rotation - 0, 90, 180 and 270 degrees
9. Supports scaling from 1/4x to 8x on video pipelines
10. Supports Wait for Vsync and Panning feature under FBDEV
11. Supports Alpha blending, both global alpha and pixel alpha
12. Supports Source and Destination color keying through V4L2 ioctls
13. Supports Modular build

Driver Features - OMAP35x, AM/DM37x

1. Supports LCD display interface at VGA resolution (480*640)

Driver Features - AM3517

1. Supports LCD display interface at resolution (480*272)

Features Not Supported

1. RGB888 rotation is not supported
2. RFBI interface is not supported
3. DSI/SDI serial interface is not supported
4. Dynamic Changing of modes (NTSC/PAL) for TV out not supported
5. Linking feature not supported on video pipelines
6. Brightness class driver is not supported
7. Mirroring is not supported

Features Not Supported - AM/DM37x

1. DVI and TV out is not supported

Constraints

1. Incorrect configuration of parameters results in Sync Lost
2. Minimum 3 Buffers are required for streaming in V4L2
3. PAL resolution can be set maximum to 720 x 574 instead of 720 x 576 because of hardware limitation
4. Upscaling and downscaling with images more that 720x574 resolution is not supported because of dss functional clock frequency limitation

Supported System Calls

open(), close(), read(), mmap(), munmap() and ioctl()

Performance Benchmarks

Setup Details -

• TV - Hitachi LCD TV (NTSC/PAL)
• DVI Monitor - Dell Monitor (720P/480P) without rotation
• File System - NFS
• CPU Idle - Disabled
• Tool Used for measurement - LFTB

Performance Benchmarks - OMAP35x

OMAP35x Display Driver Performance

Output Interface	Driver Framework	Resolution	Frame Rate (FPS)	CPU Load (%)
LCD	Fbdev	VGA (640x480)	58.831291	0.12
TV	Fbdev	NTSC(720x480)	30.189657	0.18
TV	Fbdev	PAL(720x574)	25.074780	0.0
DVI	Fbdev	720P(1280x720)	60.028236	0.12
DVI	Fbdev	480P(720x480)	59.204834	0.12
LCD	V4L2	VGA(640x480)	58.495472	0.06
TV	V4L2	NTSC(720x480)	30.001509	0.03
TV	V4L2	PAL(720x574)	25.0260724	0.03
DVI	V4L2	720P(1280x720)	59.968182	0.06
DVI	V4L2	480P(720x480)	58.669479	0.12

Performance Benchmarks - AM/DM37x

AM/DM37x Display Driver Performance

Output Interface	Driver Framework	Resolution	Frame Rate (FPS)	CPU Load (%)
LCD	Fbdev	VGA (640x480)	29.443403	0.0
LCD	V4L2	VGA(640x480)	29.247189	0.0

Performance Benchmarks - AM3517

Video Display Driver Performance

Output Interface	Driver Framework	Resolution	Frame Rate (FPS)	CPU Load (%)
LCD	Fbdev	480x272	59.447750	0.0
TV	Fbdev	NTSC(720x480)	30.050051	0.12
TV	Fbdev	PAL(720x574)	25.147581	0.10
DVI	Fbdev	720P(1280x720)	60.041698	0.12
LCD	V4L2	480x272	59.356911	0.06
TV	V4L2	NTSC(720x480)	30.000294	0.06
TV	V4L2	PAL(720x574)	25.024925	0.02
DVI	V4L2	720P(1280x720)	59.965759	0.06

Video Capture Driver

This section describes the Video Capture driver architecture, driver features and performance numbers (throughput and CPU load).

Introduction

Current V4L2 sub-system is supporting 3 different frameworks, V4L2-Int, SoC-Cam and Sub-Dev. Out of these, 2 has already become legacy framework and all future driver must use Sub-Dev frameowrk.

Although from user application point of view the interface will remain the same, driver follows standard V4L2 interface.

OMAP35x, AM/DM37x

OMAP35x and AM/DM37x Video Capture driver is based on V4L2-Int framework.

AM3517

AM3517 Video Capture driver is based on V4L2 Sub_device framework.

Driver Features

1. Supports one software channel and a corresponding device node (/dev/video0) for capture module
2. Supports mmapped (driver allocated) and user buffer exchange mechanism
3. Supports dynamic switching among input interfaces with some necessary restrictions wherever applicable
4. Supports NTSC and PAL standard on Composite and S-Video interfaces
5. Supports 8-bit BT.656 capture in UYVY and YUYV interleaved formats
6. Supports standard V4L2 IOCTLs to get/set various control parameters like brightness, contrast and saturation
7. Supports Modular build

Driver Features - OMAP35x, AM/DM37x

1. Supports both Multi-Media Daughter Card and on-board Video Decoder (NOTE:Both are mutual exclusive to each other)

Features Not Supported

1. Cropping and scaling operations and their corresponding V4L2 IOCTLs
2. Raw capture (capture through sensor interface)

Features Not Supported - OMAP35x, AM/DM37x

1. On-the-fly previewer interface is not supported
2. All internal processing block, H3A, Histogram, black level compensation, etc.. are not supported
3. CSI serial interface is not supported
4. On-the-fly resizing operation

Constraints

1. Dynamic switching of resolution and dynamic switching of interfaces is not supported when streaming is on
2. Driver buffer addresses and pitch must be aligned to 32 byte boundary

Constraints - OMAP35x, AM/DM37x

1. In case of USERPTR with VM_IO, the buffer size must be 4096 byte aligned

Constraints - AM3517

1. Greenish color is seen due to Hardware know issue, Application must implement Reverse A-Law table (Please refer to the sample application available with release for reference)

Supported System Calls

open(), close(), mmap(), munmap() and ioctl()

Performance Benchmarks

Setup Details -

• DVD Player - Sony (DVP-NS51P)
• TV - Hitachi LCD TV (NTSC/PAL) Or LCD Panel (VGA)
• File System - NFS
• CPU Idle - Disabled
• Tool Used for measurement - saUserPtrLoopback.c

Performance Benchmarks - OMAP35x

OMAP35x Capture Driver Performance

Resolution	Frame Rate (FPS)	CPU Load (%)
NTSC(720x480)	30	12.71
PAL(720x574)	25	11.42

Performance Benchmarks - AM/DM37x

AM/DM37x Capture Driver Performance

Resolution	Frame Rate (FPS)	CPU Load (%)
NTSC(720x480)	30	9.32
PAL(720x574)	25	7.68

Performance Benchmarks - AM3517

AM3517 Capture Driver Performance'

Resolution	Frame Rate (FPS)	CPU Load (%)
NTSC(720x480)	30	50
PAL(720x574)	25	42

Video Resizer Driver (Only for OMAP35x and AM/DM37x)

This section describes the Video Resizer driver architecture, driver features and performance numbers (throughput and CPU load).

Introduction

OMAP35x Video Resizer driver is simple character driver using V4L2-buffer layer for buffer management.

Driver Features

1. Resizes input frame stored in RAM and stores output frame in RAM
2. Supports resizing from 1/4x to 4x
3. Supports independent horizontal & vertical resizing
4. Supports YUV422 packed and color separate data
5. Supports driver allocated and user provided buffers including IOMEM
6. Supports Modular build

Features Not Supported

1. On-the-fly mode of operation

Constraints

1. All input,ouput addresses and pitch must be 32 bytes aligned
2. Output image size cannot be more than 2047x2047
3. Output width must be even
4. Output width must be 16 byte aligned for vertical resizing
5. The horizontal start pixel must be within range 0-15 for color interleaved and 0-31 for color separate data

Supported System Calls

open(), close(), mmap(), munmap() and ioctl()

Performance Benchmarks

Setup Details -

• File System - NFS
• CPU Idle - Disabled
• Tool Used for measurement - LFTB

Performance Benchmarks - OMAP35x

OMAP35x Resizer Driver Performance

Scaling	Time Taken (MicroSecond)	CPU Load (%)
4x (176x144 => 704x576)	1312	15.67
1/4x (704x576 => 176x144)	3205	41.67

Performance Benchmarks - AM/DM37x

AM/DM37x Resizer Driver Performance

Scaling	Time Taken (MicroSecond)	CPU Load (%)
4x (176x144 => 704x576)	1098	19.23
1/4x (704x576 => 176x144)	2625	20.00

NAND Driver

This section describes the NAND flash driver architecture, driver features and performance numbers (throughput and CPU load).

Introduction

The NAND flash driver is implemented as both - block driver and character driver, compliant with the standard MTD driver. It supports various NAND Flash chips (see drivers/mtd/nand/nand_ids.h file.) The NAND driver creates the device nodes for user space access (/dev/mtdblock0, /dev/mtdblock1, /dev/mtd0,/dev/mtd1 and so on). This release has been tested with Micron NAND device on the OMAP3EVM/AM3517EVM

This figure illustrates the stack diagram of NAND flash driver in Linux.

Driver Features

The driver supports the following features:

1. JFFS2 file system
2. Supports Read/Write, Erase operations
3. Bad Block Management
4. Polled mode of transfer
5. SLC NAND
6. NAND Flash divided into 5 partitions
   1. 512KB partition for X-loader
   2. 1920 KB (Read Only) partition for U-Boot
   3. 128 KB (Read Only) for environment variables
   4. 5 MB (Read/Write) partition for Linux
   5. Remainder for file system and others (Read/Write)

Features Not Supported

None

Constraints

None

Supported System Calls

Supports the system call support proivided by MTD interface viz. open(), close(), read(), write(), ioctl()

Performance Benchmarks

Nand Read performance values

Buffer Size (in KBytes)	OMAP35x		AM/DM37x		AM3517
	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	9.23	100	9.63	100	9.16	100
256	9.17	100	10.34	100	9.19	100
512	9.12	100	10.37	100	9.45	100
1024	8.98	100	10.31	100	9.51	100
5120	8.81	100	10.00	100	9.52	100

Nand Write performance values

Buffer Size (in KBytes)	OMAP35x		AM/DM37x		AM3517
	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	8.77	100	9.14	100	7.53	100
256	8.79	100	9.23	100	7.29	100
512	8.84	100	10.64	100	8.38	100
1024	8.81	100	10.60	100	8.01	100
5120	8.78	100	10.89	100	8.83	100

The performance numbers are captured using the following:

1. NAND PART Number: Micron MT29F4G08AAC
2. CPU Power Management disabled.
3. File System = JFFS2
4. NAND partition was mounted with async option.

MMC/SD Driver

This section provides details on MMC/SD driver along with throughput and CPU load numbers.

Introduction

The MMC controller provides an interface to external MMC cards that follow the MMC specification v4.0. The MMC driver is implemented as a block driver. Block device nodes(such as /dev/mmcblockp1, /dev/mmcblockp2) are created for user space access.

Driver Features

The driver supports the following features:

1. MMC/SD native protocol command/response set
2. Single/multiple block data transfers
3. Linux file system and generic MMC layer abstract details of block devices (MMC)
4. High-speed (SDv1.1) and High Capacity (SDv2.0) cards
5. Support for 1/4 bit modes
6. Support for card detect and Write protect features
7. DMA mode for data transfer operations
8. SDIO functionality (tested with marvell 8686 wlan card)

Features Not Supported

1. Support for 8-bit mode of operation.
2. SPI mode of operation

Constraints

1. MMC/SD cards should not be removed when the mount operation is in progress. If done so, data integrity cannot be guaranteed.

Supported System Calls

open(),close(),read(),write()

Supported IOCTLs

None

Performance and Benchmarks

Important
The performance numbers can be severely affected if the media is mounted in sync mode.

Performance Measurement using EXT2 file system

Read performance values

Buffer Size (in KBytes)	OMAP35x		AM/DM37x		AM3517
	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	19.77	22.98	19.42	16.67	19.79	24.54
256	19.79	20.79	19.68	16.82	19.79	24.86
512	19.78	23.77	19.58	15.54	19.78	24.15
1024	19.74	24.81	19.55	16.01	19.81	24.39
5120	17.50	17.06	17.62	11.76	19.80	24.57

Write performance values

Buffer Size (in KBytes)	OMAP35x		AM/DM37x		AM3517
	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	16.58	12.82	16.52	12.15	17.17	13.26
256	15.25	12.26	15.23	12.45	15.62	16.69
512	15.46	11.46	16.07	13.02	17.03	15.77
1024	16.12	12.00	16.23	10.59	16.68	17.33
5120	16.12	12.48	15.90	11.38	17.75	17.29

The performance numbers were captured using the following:

• SD Card (Sandisk Extreme III,SDHC,Class 6, 4GB)
• CPU Power Management: Disabled
• File System: ext2
• Partition was mounted with async option

Performance Measurement using VFAT file system

Read performance values

Buffer Size (in KBytes)	OMAP35x		AM/DM37x		AM3517
	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	19.30	24.49	18.93	18.05	19.43	25.46
256	19.97	25.14	20.62	18.52	19.42	24.26
512	20.00	25.48	20.67	18.77	19.47	25.23
1024	19.96	25.57	20.65	18.31	19.55	25.19
5120	19.65	25.12	20.22	18.67	19.38	25.00

Write performance values

Buffer Size (in KBytes)	OMAP35x		AM/DM37x		AM3517
	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	18.23	21.08	18.31	19.06	16.07	23.04
256	17.01	22.08	17.83	18.00	15.46	23.30
512	17.64	22.56	17.83	17.66	15.63	24.74
1024	17.67	21.04	18.32	20.42	15.63	24.11
5120	17.80	22.07	18.43	21.27	15.25	23.84

The performance numbers were captured using the following:

• SD Card (Sandisk Extreme III,SDHC,Class 6, 4GB)
• CPU Power Management: Disabled
• File System: vfat
• Partition was mounted with async option

Real Time Clock (RTC) Driver (Only for AM3517)

This section provides details on RTC (S35390A) driver along with throughput and CPU load numbers.

Introduction

AM3517 EVM supports external RTC chip S35390A over I2C1.

Driver Features

The driver supports the following features:

1. Supports IOCTLs to set/get the time/date value
2. Driver can be built as a loadable module and inserted dynamically.

Features Not Supported

• Interrupt based Wake-up and respective IOCTL's

Constraints

None

Supported System Calls

open(), close(), write(), read()

Performance and Benchmarks

None

USB Driver

This section describes the USB (EHCI and MUSB) driver architecture, features supported/not supported, constraints and performance numbers.

EHCI host Controller

Description

OMAP35x

OMAP3EVM (Rev < E) has EHCI port on Mistral Daughter Card (MDC) while on OMAP3EVM (Rev >= E) EHCI port is on main board itself.

AM/DM37x

EHCI port is on main board of OMAP3EVM (Rev G) which is used for testing OMAP37x.

AM3517

AM3517EVM has one EHCI port on base board and another EHCI port on UI card. EHCI port on UI card would work only if LCD is not enabled as LCD and UI card EHCI port share some IO pins.

Driver Features

The driver supports the following features

1. Hub Class
2. Mass Storage Class (MSC)
3. Human Interface Class (HID) (through a high speed hub)
4. USB Video Class (UVC)
5. USB Audio Class (UAC)

Features Not Supported

All other classes not mentioned in the "Supported Features" section.

MUSB OTG controller

Description

OMAP35x

The MUSB driver is implemented on top of Mentor OTG IP version 1.4 which supports all the speeds (High, Full and Low).MUSB uses inventra DMA for all the transfers. OMAP3EVM uses ISP1504 external USB PHY.

AM/DM37x

The MUSB driver is implemented on top of Mentor OTG IP version 2.0 which supports all the speeds (High, Full and Low).MUSB uses inventra DMA for all the transfers. OMAP3EVM uses ISP1504 external USB PHY.

AM3517

The MUSB driver is implemented on top of Mentor OTG IP version 1.8 which supports all the speeds (High, Full and Low).MUSB uses CPPI4.1 DMA for all the transfers. AM3517 has USB PHY inside IP itself.

Driver Features

The driver supports the following features

Host Mode

1. Hub Class
2. Human Interface Class (HID)
3. Mass Storage Class (MSC)
4. USB Video Class (UVC)
5. USB Audio Class (UAC)

Gadget mode

1. Mass Storage Class (MSC)
2. USB Networking - RNDIS/CDC

OTG mode

1. Session Request Protocol (SRP)
2. Host Negotiation Protocol (HNP)

Features Not Supported

1. All other classes not mentioned in the "Supported Features" section.

USB Mass Storage Class Host Driver

Description

This figure illustrates the stack diagram of the system with USB Mass Storage Class driver

Driver Features

The driver supports the following feature

1. DMA mode
2. PIO mode

Features Not Supported

None

Constraint

1. There is a limitation in the power that is supplied by the charge pump of the ISP1504 PHY on OMAP3EVM-1 (<=Rev-E). If you notice VBUSERR messages in the system console, then connect a self powered USB hub and then attach the device to the hub
2. OMAP3EVM-2 (>=Rev-E) can support upto 500mA power and thus self powered hub is not required.VBUS must be re-enabled after disconnect and reconnect of the MSC device while the MUSB image is built in OTG mode

Supported System Calls

open(), close(), read(), write(), ioctl()

Supported IOCTLS

None

Performance Benchmarks

---

Important

For Mass-storage applications, the performance numbers can be severely affected if the media is mounted in sync mode. Hot plug scripts in the filesystem mount removable media in sync mode to ensure data integrity. For performance sensitive applications, umount the auto-mounted filesystem and re-mount in async mode.

The numbers for USB MSC were obtained using internal benchmarking tool.

---

OMAP35x

USB MSC (MUSB) Host mode DMA Ext2 File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: ext2
3. CPU Idle state: Disabled
4. System DMA on all Rx channels: Disabled

USB-MSC MUSB Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	23.42	29.21
256	100	22.90	28.85
512	100	22.81	30.94
1024	100	24.24	32.87
5120	100	22.55	30.52

USB-MSC MUSB Host-DMA-Read Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	11.74	35.43
256	100	11.62	35.96
512	100	11.55	35.94
1024	100	11.66	35.60
5120	100	11.84	33.90

USB MSC (MUSB) Host mode DMA VFAT File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: vfat
3. CPU Idle state: Disabled
4. System DMA on all Rx channels: Disabled

USB-MSC MUSB Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	18.69	38.15
256	100	19.48	40.07
512	100	18.75	41.76
1024	100	18.99	43.56
5120	100	19.13	43.03

USB-MSC MUSB Host-DMA-Read Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	11.16	38.76
256	100	11.17	38.66
512	100	11.22	37.31
1024	100	11.42	32.86
5120	100	11.38	36.48

USB MSC (EHCI) Host mode DMA Ext2 File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: ext2
3. CPU Idle state: Disabled

USB-MSC EHCI Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	22.57	24.73
256	50	22.30	24.73
512	50	22.51	27.43
1024	50	22.00	26.85
5120	50	22.36	26.88

USB-MSC EHCI Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	21.33	31.49
256	50	21.28	36.40
512	50	21.56	35.19
1024	50	21.26	34.50
5120	50	21.47	33.33

USB MSC (EHCI) Host mode DMA VFAT File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: vfat
3. CPU Idle state: Disabled

USB-MSC EHCI Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	18.18	35.66
256	50	14.93	35.12
512	50	17.65	36.10
1024	50	17.73	36.38
5120	50	17.58	37.37

USB-MSC EHCI Host-DMA-Read Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	21.37	34.02
256	50	21.35	35.58
512	50	21.43	33.61
1024	50	21.50	33.81
5120	50	21.62	34.16

---

AM/DM37x

USB MSC (MUSB) Host mode DMA Ext2 File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: ext2
3. CPU Idle state: Disabled

USB-MSC MUSB Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	22.48	53.43
256	100	23.34	51.12
512	100	22.49	61.67
1024	100	21.28	52.94
5120	100	22.07	59.16

USB-MSC MUSB Host-DMA-Read Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	11.74	35.43
256	100	11.62	35.96
512	100	11.55	35.94
1024	100	11.66	35.60
5120	100	11.84	33.90

USB MSC (MUSB) Host mode DMA VFAT File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: vfat
3. CPU Idle state: Disabled

USB-MSC MUSB Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	16.52	53.54
256	100	16.66	54.69
512	100	15.34	64.61
1024	100	15.89	59.48
5120	100	15.95	60.02

USB-MSC MUSB Host-DMA-Read Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	11.61	37.61
256	100	11.65	37.78
512	100	11.63	36.70
1024	100	11.64	38.31
5120	100	11.63	36.81

USB MSC (EHCI) Host mode DMA Ext2 File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: ext2
3. CPU Idle state: Disabled

USB-MSC EHCI Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	22.54	51.84
256	50	21.30	49.59
512	50	21.60	50.61
1024	50	21.96	53.68
5120	50	21.01	51.31

USB-MSC EHCI Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	19.45	40.11
256	50	19.52	39.03
512	50	19.61	39.81
1024	50	19.70	40.45
5120	50	19.55	39.14

USB MSC (EHCI) Host mode DMA VFAT File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: vfat
3. CPU Idle state: Disabled

USB-MSC EHCI Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	11.94	55.62
256	50	15.90	52.59
512	50	15.55	58.72
1024	50	15.62	57.08
5120	50	15.51	57.50

USB-MSC EHCI Host-DMA-Read Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	19.55	43.71
256	50	19.69	45.22
512	50	19.52	42.06
1024	50	19.55	39.89
5120	50	19.72	40.11

---

AM3517

USB MSC (MUSB) Host mode DMA Ext2 File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: ext2
3. CPU Idle state: Disabled

USB-MSC MUSB Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	23.59	29.64
256	100	22.78	24.73
512	100	22.26	31.49
1024	100	22.25	29.15
5120	100	22.25	29.09

USB-MSC MUSB Host-DMA-Read Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	21.28	38.49
256	100	21.10	35.94
512	100	21.00	31.60
1024	100	21.13	35.35
5120	100	21.03	34.13

USB MSC (MUSB) Host mode DMA VFAT File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: vfat
3. CPU Idle state: Disabled

USB-MSC MUSB Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	19.03	38.80
256	100	18.81	37.61
512	100	17.40	40.10
1024	100	17.64	40.91
5120	100	15.36	44.91

USB-MSC MUSB Host-DMA-Read Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	100	21.05	35.76
256	100	21.10	37.35
512	100	21.10	34.68
1024	100	21.06	30.58
5120	100	21.20	37.04

USB MSC (EHCI) Host mode DMA Ext2 File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: ext2
3. CPU Idle state: Disabled

USB-MSC EHCI Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	22.09	26.81
256	50	22.49	26.25
512	50	22.35	26.55
1024	50	21.67	26.30
5120	50	21.74	26.15

USB-MSC EHCI Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	21.38	34.56
256	50	20.86	37.72
512	50	21.26	26.33
1024	50	21.33	34.69
5120	50	21.24	34.42

USB MSC (EHCI) Host mode DMA VFAT File System Performance

The performance numbers are captured using the following.

1. Hard disk: Toshiba 80GB DISK DRIVE
2. File format: vfat
3. CPU Idle state: Disabled

USB-MSC EHCI Host-DMA-Write Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	18.16	35.36
256	50	18.27	32.98
512	50	17.50	37.40
1024	50	17.53	38.19
5120	50	17.89	40.24

USB-MSC EHCI Host-DMA-Read Performance values

Buffer Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBytes/sec)	CPU Load (in %)
100	50	20.94	36.42
256	50	21.18	36.84
512	50	21.20	34.35
1024	50	21.29	37.38
5120	50	21.40	35.86

USB Mass Storage Class Slave Driver

Description

This figure illustrates the stack diagram of the system with USB File Storage Gadget driver

Driver Features

The driver supports the following feature

1. DMA mode
2. PIO mode
3. File backed storage driver was tested with SD media as the storage medium

Features Not Supported

None

Constraint

None

Supported System Calls

NA

Supported IOCTLS

NA

Performance Benchmarks

OMAP35x

USB Slave-DMA Performance

USB Slave-DMA-Read Performance values

Bytes Transferred (MB)	Number of files transferred	Total Bytes transferred (MB)	Data Rate (MB/sec)
200	1	200	4.4

USB Slave-DMA-Write Performance values

Bytes Transferred (MB)	Number of files transferred	Total Bytes transferred (MB)	Data Rate (MB/sec)
200	1	200	4.25

The performance numbers are captured using the following.

1. Storage media: Toshiba 80 GB HDD connected to EHCI port
2. File format: vfat on Windows XP
3. CPU Idle state: off
4. System DMA for Rx channel : Enabled

AM/DM37x

USB Slave-DMA Performance

USB Slave-DMA-Read Performance values

Bytes Transferred (MB)	Number of files transferred	Total Bytes transferred (MB)	Data Rate (MB/sec)
200	1	200	5.12
1000	1	1000	5.24

USB Slave-DMA-Write Performance values

Bytes Transferred (MB)	Number of files transferred	Total Bytes transferred (MB)	Data Rate (MB/sec)
200	1	200	3.6
1000	1	1000	5.0

The performance numbers are captured using the following.

1. Storage media: Toshiba 80 GB HDD connected to EHCI port
2. File format: vfat on Windows XP
3. CPU Idle state: off
4. System DMA for Rx channel : Enabled

AM3517

USB Slave-DMA Performance

USB Slave-DMA-Read Performance values

Bytes Transferred (MB)	Number of files transferred	Total Bytes transferred (MB)	Data Rate (MB/sec)
200	1	200	13.92
1000	1	1000	14.23

USB Slave-DMA-Write Performance values

Bytes Transferred (MB)	Number of files transferred	Total Bytes transferred (MB)	Data Rate (MB/sec)
200	1	200	6.81
1000	1	1000	6.89

The performance numbers are captured using the following.

1. Storage media: Toshiba 80 GB HDD connected to EHCI port
2. File format: vfat on Windows XP
3. CPU Idle state: off

USB CDC/RNDIS Slave Driver

Description

The CDC RNDIS gadget driver that is used to send standard Ethernet frames using USB. The driver will create an Ethernet device by the name usb0.

Driver Features

The driver supports the following feature

1. DMA mode
2. PIO mode
3. 10/100 Mbps speed.

Features Not Supported

None

Constraint

None

Supported System Calls

open(), close(), read(), write(), ioctl()

Supported IOCTLS

None

Performance Benchmarks

Performance benchmarks were collected using the Iperf tool and default options were used to collect the throughput numbers.

OMAP35x

USB CDC-DMA Performance

USB CDC-DMA Performance values - Client

TCP Window Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBits/sec)	Interval (in sec)
16	393	55	60
32	405	56.6	60
64	414	58	60
128	367	58	60

USB RNDIS-DMA Performance

USB RNDIS-DMA Performance values - Client

TCP Window Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBits/sec)	Interval (in sec)
16	516	72.2	60
32	493	68.4	60
64	511	71.5	60
128	469	65.5	60

AM/DM37x

USB CDC-DMA Performance

AM/DM37x CDC is not functional to capture numbers.

USB CDC-DMA Performance values - Client

TCP Window Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBits/sec)	Interval (in sec)
16	NA	NA	NA
32	NA	NA	NA
64	NA	NA	NA
128	NA	NA	NA
208	NA	NA	NA

USB RNDIS-DMA Performance

USB RNDIS-DMA Performance values - Client

TCP Window Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBits/sec)	Interval (in sec)
16	519	72.6	60
32	566	79.1	60
64	575	80.4	60
128	578	80.9	60

AM3517

USB CDC-DMA Performance

USB CDC-DMA Performance values - Client

TCP Window Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBits/sec)	Interval (in sec)
16	780	109.2	60
32	786	109.9	60
64	804	112.4	60
128	848	118.5	60
208	776	108.4	60

USB RNDIS-DMA Performance

USB RNDIS-DMA Performance values - Client

TCP Window Size (in KBytes)	Total Bytes Transferred (in MBytes)	Transfer Rate (in MBits/sec)	Interval (in sec)
16	911	127.4	60
32	948	132.5	60
64	994	138.9	60
128	955	143.5	60
208	907	133.5	60

USB Human Interface Device (HID) Driver

Description

The event sub system creates /dev/input/event* devices with the help of mdev.

Driver Features

The driver supports the following feature

1. DMA mode
2. PIO mode
3. USB Mouse and Keyboards that conform to the USB HID specifications

Features Not Supported

None

Constraint

None

Supported System Calls

NA

Supported IOCTLS

NA

Performance Benchmarks

NA

USB Isochronous Driver

Description

USB camera, speaker and mic uses isochronouse transfers. USB Video Class (UVC) is used by most of the USB cameras to capture image.

Driver Features

The driver supports the following feature

1. DMA mode
2. PIO mode
3. Support for USB Audio and video class(UVC class)

Features Not Supported

None

Constraint

None

Supported System Calls

NA

Supported IOCTLS

NA

Performance Benchmarks

NA

USB OTG Driver

Description

MUSB controller on OMAP3530EVM and AM3517EVM supports USB On The Go (OTG). OTG protocol enables runtime role switch between USB host and device. This is achieved using Session Request Protocol (SRP) and Host Negotiation Protocol (HNP).

Driver Features

The driver supports the following feature

1. Both HNP and SRP are supported

Constraint

None

Supported System Calls

NA

Supported IOCTLS

NA

Performance Benchmarks

NA

 

Power Management

Introduction

OMAP35x, AM/DM37x silicon provides a rich set of power management features. The features include Clock control at module level, multiple power and voltage domains etc.

This section provides provides an overview of power management features supported and steps to enable these features in the kernel configuration. It also provides the typical power consumption observed for different scenarios.

cpuidle

When idle loop is executed, kernel is not doing any useful 'work'. This is an opportunity to save power. The cpuidle framework helps in saving power during the idle state.

cpufreq

CPU is not loaded evenly during execution. This provides an opportunity to save power by adjusting/scaling voltage and frequency based on the current cpu load.

SmartReflex

SmartReflex is a power-management technique for controlling the operating voltage of a device to reduce its active power consumption. It helps in achieving optimal performance/power trade-off for all devices across the technology process spectrum and across temperature variations.

Features

The features supported in this release are:

• Dynamic Tick (NO_HZ) framework.
  • The cpuidle framework with MPU and Core transition to retention(RET) and OFF states.
    • The menu governor is supported.
• Static selection of VDD1 OPP via bootarg - mpurate.
  • VDD1 OPP can be scaled (if silicon supports) upto 720MHz.
  • When OPP1 is selected for VDD1, the VDD2 is set at OPP2.
  • Basic implementation for cpufreq.
• Support SmartReflex with automatic (hardware-controlled) mode of operation.

Features not supported

1. Allow drivers and applications to limit the idle state that can be entered.
2. Support for SmartReflex with manual (software-controlled) mode of operation.

Constraints

1. Only basic implementation of cpufreq is supported.
2. Some of the drivers do not leverage the power-saving features supported by the silicon. They need to enable/ disable corresponding clocks via clk_enable() and clock_disable() only when the clocks are really needed.
3. After the system is suspended, the resume operation does not succeed from the touchscreen.

Power Measurements

The measurements in this section were done on OMAP3EVM (Rev G) with NI-USB 6251 and TI power consumption tool.

• The measurements were done at identified system state for period of ~60 secs.
• Voltage and current values for VDD1 and VDD2 are measured across jumpers J6 and J5 respectively.
• SmartReflex is enabled in the kernel configuration; but is not activated at runtime.

Specific scenarios associated with the measurement are indicated in the details below.

NOTE
A ramdisk image based on minimal busybox configuration is used during these measurements. Actual numbers may vary with daemons and processes running (configured in the filesystem).

At each OPP

OMAP35x

This table indicates the voltages measured for VDD1 and VDD2 at various OPPs (selected via bootarg - mpurate). The measurements were done with the uImage created using omap3_evm_defconfig.

Power Measurements

OPP	VDD1		VDD2
	Voltage (Volts)	Current (in mA)	Voltage (Volts)	Current (in mA)
OPP1	1.004	3.351	1.071	6.432
OPP2	1.098	7.064	1.181	11.851
OPP3	1.201	15.399	1.181	11.864
OPP4	1.272	17.996	1.181	11.878
OPP5	1.342	20.821	1.180	11.889
OPP6	1.337	24.829	1.180	11.894

AM/DM37x

NOTE
This is EA (Early Adopter) release for AM/DM37x. Therefore, no measurements were done for this release.

Against specific scenarios

Scenario 1

1. Build uImage with power management disabled and dynamic tick disabled.
2. Boot the EVM with this uImage and ramdisk.

Scenario 2

1. Build uImage with power management disabled but dynamic tick enabled.
2. Boot the EVM with this uImage and ramdisk

Scenario 3

1. Build uImage with power management, power management debug, DebugFS and dynamic tick enabled; but no cpuidle.
2. Boot the EVM with this uImage and ramdisk.
3. After boot-up, mount debugfs

   $ mkdir /debug

   $ mount -t debugfs debugfs /debug

4. Execute these commands:

   $ echo 1 > /debug/pm_debug/sleep_while_idle

5. Wait for 30 secs and start the measurement.

Scenario 4

1. Build uImage with power management, power management debug, DebugFS, dynamic tick and cpuidle enabled.
2. Boot the EVM with this uImage and ramdisk.
3. After boot-up, mount debugfs

   $ mkdir /debug

   $ mount -t debugfs debugfs /debug

4. Execute these commands:

   $ echo 1 > /debug/pm_debug/sleep_while_idle

5. Wait for 30 secs and start the measurement.

Scenario 5

1. Build uImage with power management, power management debug, DebugFS, dynamic tick and cpuidle enabled.
2. Boot the EVM with this uImage and ramdisk.
3. After boot-up, mount debugfs

   $ mkdir /debug

   $ mount -t debugfs debugfs /debug

4. Execute these commands:

   $ echo 1 > /debug/pm_debug/sleep_while_idle

   $ echo 1 > /debug/pm_debug/enable_off_mode

5. Wait for 30 secs and start the measurement.

Measurements for OMAP35x

Power Measurements

Scenario	Voltage (Volts)	Current (in mA)
Scenario 1	1.207	9.166
Scenario 2	1.207	9.167
Scenario 3	1.369	0.231
Scenario 4	1.369	0.230
Scenario 5	1.371	0.140

NOTE 1
For scenarios 1 and 2 the voltage doesn't scale to required level (~1.34V) as power management is disabled.

NOTE 2
For scenarios 3, 4 and 5 the voltage scales to required level (~1.34V) as power management is enabled.

NOTE 3
SDOCM00066405 identifies a known issue where the kernel doesn't build when CONFIG_PM is disabled. The measurements for scenario 1 and 2 were taken after fixing the issue.

Measurements for AM/DM37x

NOTE
This is EA (Early Adopter) release for AM/DM37x. Therefore, no measurements were done for this release.

CAN(HECC) Driver

This section provides details on CAN(HECC) driver.

Introduction

The CAN (HECC) driver supports the Linux netdev interface. CAN driver supports TX and RX mailbox priority feature ensuring in-order packet processing at various bit rates.

Driver Features

The driver supports the following features:

1. SocketCAN networking framework
2. Linux NAPI support for Rx operations
3. Local loopback of sent frames (IFF_ECHO)
4. Standard CAN bus bit-rates namely 10K, 20K, 50K, 100K, 125K, 250K, 500K & 1M

Features Not Supported

1. ID filtering / Acceptance masks - since Linux infrastructure does not support this the driver cannot provide the feature

Constraints

NA

Supported System Calls

Supports the socket() and related system calls in accordance with Linux architecture. Refer to can.txt under Documentation/networking folder

Performance and Benchmarks

NA