i've little problems to get my IIC bus to work.
I try to read from an EEPROM, but i only get 0xFF in my data array.
I'm using the 9S12XDT512 and a Microchip 24LC16B EEPROM.
Here is my code:
Can somebody help me to get this working?int flag; // flag for the IIC-IR
int length; // datalength to read from IIC
int i; // counter for data
byte rAdr; // byte adress (EEPROM data)
byte dummy; // dummy byte for reading data
byte data[2048] = 0; // data from IIC
void IIC_Init(void)
{
IIC0_IBFD = 0x4C; // frequency divider register: Bus = 8Mhz =>SCL = 91 kHz
IIC0_IBAD = 0x00; // slave address of this module
IIC0_IBSR = 0x12; // clear the IBAL and IBIF flags
IIC0_IBCR = 0xC0; // enables ICC with interrupts
}
/******************************************************************
************************ END IIC_Init *****************************
******************************************************************/
/******************************************************************
Function: void IIC_Read(unsigned char read_addr)
Developer: nic_mcp
Parameters: read_addr: address of slave;
Returns: Nothing
Description: read EEPROM data
******************************************************************/
void IIC_Read(unsigned char read_addr, int len)
{
flag=10;
length = len;
i=0;
rAdr = read_addr;
IIC0_IBCR_MS_SL = 1; // set transmit and master mode
IIC0_IBCR_TX_RX = 1; // and generate start condition
IIC0_IBDR = 0xb1; // Send Slave Adress with read mode
}
/******************************************************************
************************ END IIC_Read *****************************
******************************************************************/
/******************************************************************
Function: void IIC_IR()
Developer: nic_mcp
Parameters: none
Returns: Nothing
Description: called by interrupt
******************************************************************/
void IIC_IR()
{
IIC0_IBSR = 0x12; // clear the IBAL and IBIF flags
switch(flag)
{
case 10:
{
IIC0_IBDR = rAdr;
flag++;
return;
}
case 11:
{
IIC0_IBDR = rAdr;
flag++;
return;
}
case 12:
{
IIC0_IBCR_RSTA = 1; // set up repeated start
IIC0_IBDR = 0xa1;
flag++;
IIC0_IBCR_TX_RX = 0;
IIC0_IBCR_TXAK = 0;
return;
}
case 13:
{
if (length>1)
{
data[i] = IIC0_IBDR; // read data from bus
length--;
i++;
return;
} else
{
IIC0_IBCR_TXAK = 1; // ACK disabled
i++;
length--;
flag++;
return;
}
}
case 14:
{
IIC0_IBCR_MS_SL = 0; // create stop condition
flag = 0;
return;
}
}
}
/******************************************************************
************************ END IIC_IR *******************************
******************************************************************/
/******************************************************************
Function: void main(void)
Developer: nic_mcp
Parameters: none
Returns: Nothing
Description: main-method
******************************************************************/
void main(void)
{
/* put your own code here */
EnableInterrupts;
IIC_Init(); // initialize the IIC-modul
IIC_Read(0x00,2048); // read EEPROM
for(;
{
} /* wait forever */
/* please make sure that you never leave this function */
}
/******************************************************************
************************ END main *********************************
******************************************************************/
thx nic_mcp
Added p/n to subject.
Message Edited by NLFSJ on 2007-11-29 02:50 PM
Hi nic_mcp,
I have attached my old project for 24C16 & DP256 for reference.
It worked fine. But you can do the things little bit easier than me.
I hope it helps.
More information about S12 & S08 I2C module with complete SW routines you can find in AN3291
