Issue with I2C on MPC5606B

malekben — Thu, 13 Nov 2014 19:55:00 GMT

Hi all,

I am encountering an issue with my I2C communication :

I am trying to TRANSMIT data in MASTER mode but my program stuck while waiting for IBSR[IBIF] to get set.

This is the code that I am using :

//Clear Interrupt Flag

pstIBSRReg = (TstDI2c_iIBSRBits *)(Ctu32DI2c_iBaseAdress[Fu16I2cLink] + Du32DI2c_iIBSROffset);

(* pstIBSRReg).u1IBIF = 1U;

//Make sure bus is idle -> IBB must be cleared

while (1U == (* pstIBSRReg).u1IBB) {}

//Generate start condition

pstIBCRReg = (TstDI2c_iIBCRBits *)(Ctu32DI2c_iBaseAdress[Fu16I2cLink] + Du32DI2c_iIBCROffset);

(* pstIBCRReg).u1TXRX = 1U; // Transmit

(* pstIBCRReg).u1MSSL = 1U; // Master Mode

//Wait for IBSR.IBB (bus busy) to be set

while (0U == (* pstIBSRReg).u1IBB) {}

//Put target address into IBDR

pstIBDRReg = (TstDI2c_iIBDRBits *)(Ctu32DI2c_iBaseAdress[Fu16I2cLink] + Du32DI2c_iIBDROffset);

(* pstIBDRReg).u8DATA = ((Fu8SlaveID<<1) | Du8DI2c_iWriteSlave);

// Wait for address transfer to be done

while (0U == (* pstIBSRReg).u1IBIF) {}

// Clear Interrupt Flag

(* pstIBSRReg).u1IBIF = 1U;

My program stuck at "while (0U == (* pstIBSRReg).u1IBIF) {}".

It is normal because the transfer was not initiated at all since that IBDR register value remains equal to 0x00.

Knowing that :

- START signal was correctly generated (verified with a scope).

- After generating the start signal and before writing into IBDR, I2C rgisters value are as below :

* IBCR = 0x30 // MDIS = 0 / MSSL = 1 / TXRX = 1

* IBSR = 0xA0 // TCF = 1 / IBB = 1

- I tried to write directly on the memory address 0xFFE30004 (IBDR address) but it still always equal to 0x00.

My question is what would forbid writing the IBDR register ?

Best regards,

Malek BEN.

Re: Issue with I2C on MPC5606B

BlackNight — Mon, 24 Nov 2014 08:53:28 GMT

Could it be that you run into a silicon errata problem with repeated start condition on I2C?

Erich