Omega Engineering OME-A8111 manual 9 A/D Software Trigger Control Register

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The pacer trigger can control the sampling rate very precisely. So the converted data can be used to reconstruct the waveform of the analog input signal. In pacer trigger mode, the pacer timer will periodically generate trigger signals to the A/D converter. This converted data can be transfer to the CPU by polling or interrupt or DMA transfer method.

The software driver provides three polling or interrupt-transfermethods. The polling subroutine, A8111_AD_PollingVar() or A822_AD_PollingArray(), sets the A/D mode control register to 0x01. This control word means software trigger and polling transfer. The interrupt subroutine, A822_AD_INT_START(…), sets the A/D mode control mode register to ox06. This control word means pacer trigger and interrupt transfer. The interrupt subroutine, A822_AD_DMA_START(…), sets the A/D mode control register to 0x06 This control word means pacer trigger and DMA transfer.

2.4.9A/D Software Trigger Control Register

(WRITE)

Base+C : A/D Software Trigger Control Register Format

 

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

X

X

X

X

X

X

X

X

X=don‘t care, XXXXXXXX=any 8 bits data is validate

The A/D converter can be triggered by software trigger or pacer trigger. Detailed information is given in sec.2.4.8 and 2.7. Writing any value to address BASE+C will generate a trigger pulse to the A/D converter and initiate an A/D conversion operation. The address BASE+5 offers a ready bit to indicate that an A/D conversion is complete.

The software driver uses this control word to detect the OME-A-8111 hardware board. The software initiates a software trigger and checks the ready bit. If the ready bit cannot clear to zero in a fixed time, the software driver will return an error message. If there is an error in the I/O BASE address setting, the ready bit will not be cleared to zero. The software driver, A8111_CheckAddress(), uses this method to detect the status of the I/O BASE address setting.

OME-A-8111 Hardware Manual (ver.1.1, Jul/2003)

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Contents User’sGuide Czech Republic CanadaMexico BeneluxOME-A-8111 Table of Contents Calibration General Description Features3 A/D Converter SpecificationsPower Consumption Analog InputsDigital I/O DA ConverterInterrupt Channel Product Check List Programmable Timer/CounterApplications Board Layout Hardware ConfigurationDefault base address is I/O Base Address Setting1 JP1 D/A Internal Reference Voltage Selection Jumper SettingAddress Read Write I/O Register Address2 A/D Input Buffer Register 8254 Counter4 D/I Input Buffer Register 3 D/A Output Latch Register 6 A/D Gain Control Register Clear Interrupt Request7 A/D Multiplex Control Register SI2 SI1 SI0 8 A/D Mode Control Register9 A/D Software Trigger Control Register 10 D/O Output Latch Register CN3 Digital I/OCounter 8254 Timer/CounterSec A/D Conversion2 A/D Conversion Trigger Modes If switching from one channel to the next secPacer Trigger Mode 1 A/D conversion flow3 A/D Transfer Modes Using software trigger and polling transferD/A Conversion Signal Shielding Analog Input Signal ConnectionCN1 Analog input/Analog output/Connect Pin Assignment Pin AssignmentCN3 Analog input/Analog output/Connect Pin Assignment CN2 Analog input/Analog output/Connect Pin AssignmentOME-DB-16R Daughter BoardOME-CA-4002 OME-DB-16PCalibration VR Description CalibrationD/A Calibration Steps DI/O TestingA/D Calibration Steps WARRANTY/DISCLAIMER Temperature
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