Software Trigger and Polling Techniques

The steps below should be followed for software triggering and polling:

1.Send 00h to A/D mode control register (software trigger + polling transfer)

2.Send channel number to multiplexer control register.

3.Send the gain control code value to gain control register.

4.Send any value to software trigger control register to generate a software trigger signal.

5.Scan the READY bit of the A/D high byte data until READY=0

6.Read the 12 bits A/D data.

7.Convert the 12 bits binary data to the floating point value.

For example:

/* -------------------------------------------------------------		*/
/* DEMO 3: AdPolling		*/
/* Compiler: Borland C++ 3.1, Mode Large		*/
/* Output Code: HEX code		*/
/* --------------------------------------------------------------		*/
#include "P1002.H"
WORD wBaseAddr,wIrq;
//-------------------------------------------------------
WORD P1002_Delay(WORD wDownCount)
{
WORD h,l;
int count;
wDownCount &= 0x7fff;
if (wDownCount<1) wDownCount=1;
/* Clock in=4M --> count 4000 = 1 ms, count 1 = 0.25 us */
l=wDownCount&0xff;
wDownCount=wDownCount / 256;
h=wDownCount&0xff;
outp(wBaseAddr+3*4,0xB0);	/* mode_0, counter_2 */
outp(wBaseAddr+2*4,l);	/* counter_2 low byte first */
outp(wBaseAddr+2*4,h);	/* counter_2 high byte ,0x07D0=2000 */
outp(wBaseAddr+3*4,0x80);	/* latch counter_2 */

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