rrb011270
Joined: 07 Sep 2003
Posts: 51
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| Any help on I2C Interrupt? |
 Posted: Mon Oct 06, 2003 12:35 am |
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Mabuhay!
Anybody in this forum who can provide help such that the code below will be converted to... using I2C interrupt.
I have an 8 chips network using I2C protocol and I want to use the interrupt during the writing and reading of the FM24C256 from Ramtron?
Anyone who can help... a sample code is a good start for me...
My code is below:
| Quote: |
/***************
* Include File *
***************/
#include <18F452.H> // type of PIC use in this project
/*************************************************
* Compiler Directives and Hardware Configuration *
*************************************************/
//#device ICD=TRUE // with an ICD debugger
#fuses HS,NOLVP,NOWDT,PUT // high speed, no watch dog timer
#use delay (clock=20000000) // 20MHz clock
/* use serial port monitor for debugging */
#use rs232(baud=115200, xmit=PIN_C6, rcv=PIN_C7)
/* I2C Configuration */
#ifndef F_RAM_SDA
// for software I2C
//#define F_RAM_SDA PIN_B1
//#define F_RAM_SCL PIN_B0
/* for hardware I2C */
#define F_RAM_SDA PIN_C4 // i2c data
#define F_RAM_SCL PIN_C3 // i2c clock
#define F_RAM_WP PIN_C5 // write protect
#endif
/* use I2C protocol using hardware */
#use i2c(master,sda=F_RAM_SDA, scl=F_RAM_SCL, FORCE_HW, FAST)
//#zero_ram // optional pre-processor declaration
/****************
* Include Files *
****************/
#include <GET_FUNCTION.C> // get function driver
#include <LCD.C> // lcd display driver
/************************
* Defines and Constants *
************************/
/* memory page length in bytes */
#define FRAM_PAGE_LENGTH 32 // page length in bytes
/* memory PAGE COUNT IN NUMBER OF PAGES */
#define FRAM_PAGE_ONE 1024 // number of pages for 1 chip
#define FRAM_PAGE_COUNT 8192 // number of pages for 8 chips
/* total number of chips */
#define FRAM_CHIP_COUNT 8 // total number of chips
/* define a byte to write at F-RAM for R/W test */
#define DATA_TEST_x55 0x55
#define DATA_TEST_xAA 0xAA
/* define F-RAM address and size */
//#define F_RAM_ADDRESS long int
//#define F_RAM_SIZE 32768
#define F_RAM_ADDRESS int32
#define F_RAM_SIZE 262144
/* define I2C read/write address */
#define F_WR_ADDRESS 0xA0 // initial F-RAM write address at 1st chip
#define F_RD_ADDRESS 0xA1 // initial F-RAM read address at 1st chip
/* F-RAM Initialization */
void init_ext_f_ram()
{
output_float(F_RAM_SCL);
output_float(F_RAM_SDA);
}
/* memory write by address routine */
void memory_write_by_addr(int32 i32Address, byte bData)
{
int8 iChipselect;
// Determine which chip to address
iChipselect = (F_WR_ADDRESS | make8(i32Address<<2,2)) & 0xFE;
output_low(F_RAM_WP); // set write protect low
while (TRUE)
{
i2c_start();
// look for the ACK from the device to ensure the
// devide is ready
if (i2c_write(iChipselect ) == 0) break;
}
// Max of 32K of address. The MSB is handled in the iChipselect
i2c_write((make8(i32Address,1)) & 0x7F);
i2c_write(make8(i32Address,0));
i2c_write(bData);
i2c_stop();
output_high(F_RAM_WP); // set write protect high
}
/* memory read by address routine */
byte memory_read_by_addr(int32 i32Address)
{
byte bData;
int8 iChipselect;
// Determine which chip to address
iChipselect = (0xA0 | make8(i32Address<<2,2)) & 0xFE;
while (TRUE)
{
i2c_start();
// look for the ACK from the device to ensure the
// devide is redy
if (i2c_write(iChipselect) == 0) break;
}
// Max of 32K of address. The MSB is handled in the iChipselect
i2c_write((make8(i32Address,1)) & 0x7F);
i2c_write(make8(i32Address,0));
i2c_start();
// set the LSB for reading
i2c_write(iChipselect | 0x01);
bData=i2c_read(0);
i2c_stop();
return(bData);
}
/* write memory byte routine */
void write_memory_byte(long int liAddress,byte bData,int iNew_wr_addr)
{
short int siStatus;
output_low(F_RAM_WP); // set write protect low
while (TRUE) {
i2c_start();
// look for the ACK from the device to ensure the
// devide is redy
if (i2c_write(iNew_wr_addr) == 0) break;
}
i2c_write(liAddress>>8);
i2c_write(liAddress);
i2c_write(bData);
i2c_stop();
output_high(F_RAM_WP); // set write protect high
}
/* read memory byte routine */
byte read_memory_byte(long int liAddress,int iNew_wr_addr)
{
byte bData;
while (TRUE)
{
i2c_start();
// look for the ACK from the device to ensure the
// devide is redy
if (i2c_write(iNew_wr_addr) == 0) break;
}
i2c_write(liAddress>>8);
i2c_write(liAddress);
i2c_start();
i2c_write((iNew_wr_addr | 0x01));
bData=i2c_read(0);
i2c_stop();
return(bData);
}
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I appreciate any help on how can I convert this code such that it will utilize the I2C interrupt (#INT_SSP)...
I really need help here... a sample code will be great!!! as a start for me..
BTW, the PIC18F452 will act as the master.... my application is just write, read and read/write testing to FRAM chip using I2C interrupt..
Note I have the 8 chip wired to have their own addresses....
Thnx[/quote] |
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