SN74HC165: Reading serial output from a shift register IC

Hi, thanks for replying.

How can we read the serial data from a GPIO?

Regards,
Apurv

Hello!

I have written this code for SN74LV8154 binary counter IC but it is not counting continuously, it resets at 7 or sometimes at a lower value only.

// include files
#include "HL_sys_common.h"
#include "HL_gio.h"
#include "HL_sci.h"
#include "HL_het.h"
#include <stdio.h>

#define GAL 2
#define GAU 18
#define GBL 16
#define GBU 30
#define RCLK 14
#define CCLR 12
#define CLK 22

char count[20];

void main()
{
unsigned long freq = 0;
uint8 b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18,b19,b20,b21,b22,b23,b24,b25,b26,b27,b28,b29,b30,b31;

// Initialize GIO driver
gioInit();

// Initialize SCI driver
sciInit();

// Initialize HET driver
hetInit();

// setting HET1 driver pins as output
gioSetDirection(hetPORT1, 0xFFFFFFFF);

//setting GIOA and GIOB driver pins as input
gioSetDirection(gioPORTA, 0x00000000);
gioSetDirection(gioPORTB, 0x00000000);

// initialization of the register
gioSetBit(hetPORT1, GAL, 1);
gioSetBit(hetPORT1, CCLR, 0);
gioSetBit(hetPORT1, GAU, 1);
gioSetBit(hetPORT1, GBL, 1);
gioSetBit(hetPORT1, GBU, 1);
gioSetBit(hetPORT1, RCLK, 0);
gioSetBit(hetPORT1, CCLR, 1);
gioSetBit(hetPORT1, CLK, 0);

while (1)
{
freq = 0;

// set CLOCK pulse
gioSetBit(hetPORT1, CLK, 1);
gioSetBit(hetPORT1, CLK, 0);

// set RCLK pulse
gioSetBit(hetPORT1, RCLK, 1);
gioSetBit(hetPORT1, RCLK, 0);

// read GBU byte
gioSetBit(hetPORT1, GBU, 0);

// read bits
b31 = gioGetBit(gioPORTB, 3);
freq = freq|b31;
freq<<=1;
b30 = gioGetBit(gioPORTB, 2);
freq = freq|b30;
freq<<=1;
b29 = gioGetBit(gioPORTA, 7);
freq = freq|b29;
freq<<=1;
b28 = gioGetBit(gioPORTA, 6);
freq = freq|b28;
freq<<=1;
b27 = gioGetBit(gioPORTA, 5);
freq = freq|b27;
freq<<=1;
b26 = gioGetBit(gioPORTA, 2);
freq = freq|b26;
freq<<=1;
b25 = gioGetBit(gioPORTA, 1);
freq = freq|b25;
freq<<=1;
b24 = gioGetBit(gioPORTA, 0);
freq = freq|b24;
freq<<=1;

// set GBU to HIGH again
gioSetBit(hetPORT1, GBU, 1);

// read GBL byte
gioSetBit(hetPORT1, GBL, 0);

// read bits
b23 = gioGetBit(gioPORTB, 3);
freq = freq|b23;
freq<<=1;
b22 = gioGetBit(gioPORTB, 2);
freq = freq|b22;
freq<<=1;
b21 = gioGetBit(gioPORTA, 7);
freq = freq|b21;
freq<<=1;
b20 = gioGetBit(gioPORTA, 6);
freq = freq|b20;
freq<<=1;
b19 = gioGetBit(gioPORTA, 5);
freq = freq|b19;
freq<<=1;
b18 = gioGetBit(gioPORTA, 2);
freq = freq|b18;
freq<<=1;
b17 = gioGetBit(gioPORTA, 1);
freq = freq|b17;
freq<<=1;
b16 = gioGetBit(gioPORTA, 0);
freq = freq|b16;
freq<<=1;

// set GBL to HIGH again
gioSetBit(hetPORT1, GBL, 1);

// read GAU byte
gioSetBit(hetPORT1, GAU, 0);

// read bits
b15 = gioGetBit(gioPORTB, 3);
freq = freq|b15;
freq<<=1;
b14 = gioGetBit(gioPORTB, 2);
freq = freq|b14;
freq<<=1;
b13 = gioGetBit(gioPORTA, 7);
freq = freq|b13;
freq<<=1;
b12 = gioGetBit(gioPORTA, 6);
freq = freq|b12;
freq<<=1;
b11 = gioGetBit(gioPORTA, 5);
freq = freq|b11;
freq<<=1;
b10 = gioGetBit(gioPORTA, 2);
freq = freq|b10;
freq<<=1;
b9 = gioGetBit(gioPORTA, 1);
freq = freq|b9;
freq<<=1;
b8 = gioGetBit(gioPORTA, 0);
freq = freq|b8;
freq<<=1;

// set GAU to HIGH again
gioSetBit(hetPORT1, GAU, 1);

// read GAL byte
gioSetBit(hetPORT1, GAL, 0);

// read bits
b7 = gioGetBit(gioPORTB, 3);
freq = freq|b7;
freq<<=1;
b6 = gioGetBit(gioPORTB, 2);
freq = freq|b6;
freq<<=1;
b5 = gioGetBit(gioPORTA, 7);
freq = freq|b5;
freq<<=1;
b4 = gioGetBit(gioPORTA, 6);
freq = freq|b4;
freq<<=1;
b3 = gioGetBit(gioPORTA, 5);
freq = freq|b3;
freq<<=1;
b2 = gioGetBit(gioPORTA, 2);
freq = freq|b2;
freq<<=1;
b1 = gioGetBit(gioPORTA, 1);
freq = freq|b1;
freq<<=1;
b0 = gioGetBit(gioPORTA, 0);
freq = freq|b0;

// set GAL to HIGH again
gioSetBit(hetPORT1, GAL, 1);

printf("%d\r\n", freq);
}
}

Where am I going wrong?

Regards,
Apurv

Hi Apurv,

Unfortunately, we don't debug code in this forum. If Clemens is available for this then that's fine, but I need schematics and scope shots that show the device not working in the manner you expect. This will provide more insight to see if the device has been damaged or if there are issues with the implementation. If you are able to provide these things then I will be able to support you further.  

I do not know anything about the microcontroller you're using, so I cannot say anything about your code.

But your description ("resets at 7 or sometimes at a lower value") sounds as if there is something wrong with the clock or the clear inputs. For that, schematic and scope/logic analyzer shots are necessary.