">gated< Frequency generation with 6602 on Linux"

[M.Behn]

"I use one of the example programms from the Measurement Hardware Driver
Development Kit.

It is the example programm gpct_ex3.cpp.


So it works fine, but now I try to modify it, it should only have a output
signal, when the gate is on high level.


This is what I want to use to create a gated PRF for triggering my radar
system.


However what do I have to modify in which way to get the described
behaviour?


Here is the exsample programm:


***********************************
/*
* gpct_ex3.cpp
*
* Continuous Pulses Generation
*
* Generate continuous pulses using counter 0. The time the pulse is
asserted is set
* in the Load B register and the amount of time spent de-asserted is set in
the Load A
* register.
*
* Attach an oscilliscope to pin 5 (PFI 36) to observe the generated pulses.
*/


#include "stdio.h"
#include "osiBus.h"
#include "tTIO.h"


void test(iBus *bus);
void initMite(iBus *bus);


int main()
{
iBus* bus;


//Each PCI card has an identifying 32bit PCI ID number.
//0x10930000 is the manufacturer ID number for all National Instruments
cards
//0x00001310 is the device ID number for the PCI-6602
//0x00001360 is the device ID number for the PXI-6602
//0x00002DB0 is the device ID number for the PCI-6608
//0x00002CC0 is the device ID number for the PXI-6608


bus = acquireBoard(0x10931310);


if(bus == NULL){
printf("Error accessing the PCI device. Exiting.\n");
return 1;
}


//Intitialise Mite Chip.


initMite(bus);


//Calling test function


test(bus);


releaseBoard(bus);
return 0;
}


//Tell the MITE to link the BAR1 address to the DAQ Board
//You must initialize the MITE before you write to the rest of the PCI board
void initMite(iBus *bus)
{
tAddressSpace Bar0;
u32 physicalBar1;


//Skip MITE initialization for PCMCIA boards
//(which do not have a MITE DMA controller)
if(!bus->get(kIsPciPxiBus,0)) return;


Bar0 = bus->createAddressSpace(kPCI_BAR0);


//Get the physical address of the DAQ board
physicalBar1 = bus->get(kBusAddressPhysical,kPCI_BAR1);


// ***** 6602/6608 specific MITE initialization *****
// Hit the IO Window Base/Size Register 1 (IOWBSR1) in the MITE. We set
the
// address, enable the window and set the size of the window:
Bar0.write32(0xC4, (physicalBar1 & 0xffffff00L) | 0x8C);


// Write to the IO Window Control Register 1 (IOWCR1) to make the IO window
// go to RAM memory space instead of the config space
Bar0.write32(0xF4, 0);


// ***** End of 6602/6608 specific code *****


bus->destroyAddressSpace(Bar0);
}


void test(iBus *bus)
{
tAddressSpace cardSpace;
tTIO *board;


cardSpace = bus->createAddressSpace(kPCI_BAR1);
board = new tTIO(cardSpace);


//Reset
board->G01_Joint_Reset_Register.writeG0_Reset(1);


//load pulsewidths into load registers A and B
//A is the low count
//B is the high count
board->G0_Load_A_Registers.writeG0_Load_A(0x00001000);
board->G0_Load_B_Registers.writeG0_Load_B(0x00002000);
board->G0_Command_Register.writeG0_Load(1);


//reload from the other load register on each terminal count
board->G0_Mode_Register.writeG0_Reload_Source_Switching(1);
board->G0_Mode_Register.writeG0_Loading_On_TC(1);


//set source to internal timebase 3, the 80MHz internal clock
board->G0_Input_Select_Register.writeG0_Source_Select(30);


// **** this should be changed? *****
//set gate to disabled gating
board->G0_Input_Select_Register.writeG0_Gate_Select(30); //Logic Low
board->G0_Mode_Register.writeG0_Gate_Polarity(1);
board->G0_Command_Register.writeG0_Synchronized_Gate(1);
board->G0_Mode_Register.writeG0_Trigger_Mode_For_Edge_Gat e(3);
board->G0_Mode_Register.writeG0_Gating_Mode(1);
// **** this should be changed? *****


//set counting direction to down
board->G0_Command_Register.writeG0_Up_Down(0);


//set PFI line to output
board->IO_Pin_36_37_Configuration_Register.writeIO_Pin_36 _Select(1);
board->G0_Mode_Register.writeG0_Output_Mode(10);


//arm counter
printf("counter value is 0x%08lx\n",
board->G0_Save_Registers.readRegister());
board->G0_Command_Register.writeG0_Arm(1);


delete board;
bus->destroyAddressSpace(cardSpace);
}


**************************************
Thanks


Mario Behn"