5.4.3 Software Triggers and Polling Techniques
The easiest way to control is by following these steps:
1. Send 00h to A/D mode control register (software t 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 until READY bit =1
6. Read the 12-bit A/D data.
7. Convert this 12-bit 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(wB3*4,0xB0);
/* mode_0, counter_2 */
outp(wB2*4,l);
/* counter_2 low byte first */
outp(wB2*4,h);
/* counter_2 high byte ,0x07D0=2000 */
outp(wB3*4,0x80);
/* latch counter_2 */
l=inp(wB2*4);
/* delay starting two CLKs */
h=inp(wB2*4);
PCI-1002 Series User Manual (Ver.2.8, Oct. 2011, PMH-015-28)
46
