Content originally posted in LPCWare by hiroshiiwasaki on Mon Feb 15 00:39:16 MST 2016
Hello My name is Hiroshi Iwasaki and one of our customer is using LPC1343 and faced I2C problem now.
Customer is testing I2C by using LPCXpresso Board OM13045 now.
Problem
They set I2C Pin configuration and De-assert as below.
LPC_IOCON->PIO0_4 = 0x01; // PIO0_4 as SCL
LPC_IOCON->PIO0_5 = 0x01; // PIO0_5 as SDA
LPC_SYSCON->PRESETCTRL |= 0x02; // De-asset I2C reset
And waiting for I2C interrupt but no interrupt was occurred.
Read back pin data is always ZERO this mean GPIO not I2C Pin.
IOCON (LPC1434) 0X40044030 = All Zero
0x40004404C= All Zero
Test
include "LPC13xx.h"
#include "SC16IS740I2C.h"
#include "GPIO.h"
#include "IF.h"
#include <cr_section_macros.h>
#include <NXP/crp.h>
// __CRP const unsigned int CRP_WORD = CRP_NO_CRP ;
int main(void) {
volatile static int i = 0;
volatile unsigned l, j, k ;
volatile unsigned char sw;
LPC_SYSCON->PRESETCTRL |= 0x02; // De-asset I2C reset
LPC_IOCON->PIO0_4 = 0x01; // PIO0_4 as SCL
LPC_IOCON->PIO0_5 = 0x01; // PIO0_5 as SDA
LPC_SYSCON->SYSAHBCLKCTRL |= (1<<5);// Enable for I2C clock LPC_SYSCON->PRESETCTRL |= 0x02; // De-asset I2C reset
LPC_I2C->SCLL = 350; // SCL Low
LPC_I2C->SCLH = 350; // SCL High
NVIC_EnableIRQ(I2C_IRQn); // Enable I2C interrupt
LPC_I2C->CONCLR = 0x6c; // I2C flagClear LPC_I2C->CONSET = 0x40; // I2C enable
LPC_I2C->CONSET = 0x20; // assert Start
// Enter an infinite loop, just incrementing a counter
while(1) {i++ ;}
return 0 ;
}
void I2C_IRQHandler(void)
{
uint8_t StatValue;
int adrs=SC16IS740_LCR_ADR;
int dat =SC16IS740_LCR_DATA;
static int t=1;
StatValue= LPC_I2C->STAT;
switch ( StatValue )
{
case 0x08: //Now Status is Start
LPC_I2C->DAT =SC16IS740_ADDR; //Device address 1010 000 + Write
LPC_I2C->CONCLR = 0x28; //clear interrupt flag + set next action
break;
case 0x18: //Now Status is SLA+W and Receive ACK
LPC_I2C->DAT =adrs; //Address
LPC_I2C->CONCLR = 0x08; //clear interrupt flag
break;
case 0x28: //Now Status is sending Data byte and Receive ACK
if(t==1){ // 1st : Data byte is address
LPC_I2C->DAT = dat; // write data
LPC_I2C->CONCLR = 0x08;
} else { // 2nd : Data byte is write data
LPC_I2C->CONSET = 0x10; //send stop command
LPC_I2C->CONCLR = 0x08; //Clear interrupt
while(LPC_I2C->CONSET & 0x00000010); //waiting STOP flag
LPC_I2C->CONCLR = 0x48; //Clear interrupt & Disable I2c
}
++t;
break;
default:
break;
}
}
Please advice to clear this problem
