StarterWare ADC

ADC

Introduction

The touchscreen/ADC module is an 8 channel general purpose ADC,with optional support for interleaving Touch screen onversation for 4-wire,5-wire, or 8-wire resistive panel. It also has a programable FSM sequencer that supports 16 steps.A step is a general term for describing which input values to send to the AFE,and how,when , and which channel to sample. For more information on steps please refer to touchscreen/ADC TRM.

Programing Sequence

The ADC can be programmed in the below sequence for desired operation.

• Enable module clocks for ADC is by invoking TSCModuleClkConfig() API.
• Multiplex AN0 - AN7 input pins invoking TouchScreenPinMuxSetUp().
• Input ADC Clock is configured by invoking TSCConfigureAFEClock() API.
• Step Configuration register are write protected.Thus,before configuring any step register, write protection for step configuration register must be disabled by invoking TSCStepConfigProtectionDisable()
• Configuring Steps.
  • A step can be configured to select required input channel and refernce volatage by invoking TSCTSStepConfig()
  • A step can be configured to drive xpp,xnp and ypp pin to high,which in trun pull up the AN0-AN2 line by invoking TSCTSStepAnalogSupplyConfig().
  • A step can be configured to drive the xnn,ypn,ynn and wpn pins to low,which in trun pull down AN1-AN4 line by invoking TSCTSStepAnalogGroundConfig() API.
  • A step can configured to store data,which is an outcome after a step is applied by fsm,in either FIFO0 or FIFO1 by invoking TSCTSStepFIFOSelConfig() API.
  • A step can configured in continous or oneshort mode for software enabled or HW event mapped step.
• ADC can be configured for differential or singled ended mode of operation by invoking TSCTSStepOperationModeControl() API.
• AFE can be configured for 4-wire or 5-wire or as general purpose inputs by invoking TSCTSModeConfig()
• Required steps can be enabled by invoking TSCConfigureStepEnable() API.
• ADC is enabled by invoking TSCModuleStateSet() API.