TMS570 I2C Initiation

I've check with the scope, trigger on SCL.

Start condition does not occur.  No output of clock or data.

This is with the Halcogen way of setting I2C up as well as using the TRM settings discussed in the previous post.

PINMUX is set for I2C.

Code structure in FDF:

i2cCustomInit(5U);
i2cSetStart(i2cREG1);
i2cSendByte(i2cREG1, 0xA8); //address of dut and write (0)
i2cSendByte(i2cREG1, 0x00); //write address
i2cSendByte(i2cREG1, 0x00); //write address
i2cSendByte(i2cREG1, 0xAA); //data
i2cSetStop(i2cREG1);

Using i2cSend:

i2cInit();

i2cSetSlaveAdd(i2cREG1,0xA8);
i2cSetStart(i2cREG1);
i2cSend(i2cREG1,3,i2cstuff);

i2cSetStop(i2cREG1);

That am I missing?

Cheers,

Alan

Alan,

Sorry for the delay in answering. I have asked an I2C expert to comment.

Regards, Sunil

Alan,

The discussion in this thread would show you how to set up I2C. However, the example code does not use Halcogen.

http://e2e.ti.com/support/microcontrollers/hercules/f/312/p/329591/1168896.aspx

Thanks and regards,

Zhaohong

Hi Zhaohong,

Thanks for the link, I will amend my code with the corrections I could see and report back.  

I advise an update of Halcogen is needed as it does not follow the setup described in the TRM or the code in the link you provided.

Cheers

Alan 

Hi,

I've tried the code suggested but the I2C is still not working. the TMS570 is connected to a single FM24CL64B with a pull up of 2k2 on both the SDA and SCL lines, the WP is set to logic low.

Setup is as follows:

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

i2cREG1->MDR = 0x0000;

i2cREG1->PFNC = 0x0000;

i2cREG1->DOUT = (uint32)((uint32)0U << 1U) //SDA
| (uint32)(0U); //SCL

i2cREG1->DIR = (uint32)((uint32)1U << 1U) //SDA - Output
| (uint32)(1U); //SCL - Output

i2cREG1->PDR = (uint32)((uint32)0U << 1U) //SDA
| (uint32)(0U); //SCL

i2cREG1->PDIS = (uint32)((uint32)0U << 1U) //SDA
| (uint32)(0U); //SCL

i2cREG1->PSEL = (uint32)((uint32)1U << 1U) //SDA
| (uint32)(1U); //SCL

i2cREG1->EMDR = 0U;

i2cREG1->OAR = 0x7F;

i2cREG1->PSC = 10U;

i2cREG1->CKH = 5U;

i2cREG1->CKL = 5U;

i2cREG1->MDR = (uint32)((uint32)0U << 15U) //NACK mode
| (uint32)((uint32)0U << 14U) //Free running
| (uint32)((uint32)0U << 13U) //Start condition
| (uint32)((uint32)1U <<11U) //Stop condition
| (uint32)((uint32)1U <<10U) //Master/Slave mode
| (uint32)((uint32)I2C_TRANSMITTER) //Transmitter/Receiver
| (uint32)((uint32)I2C_7BIT_AMODE) //Expanded address
| (uint32)((uint32)0U << 7U) //Repeat mode
| (uint32)((uint32)0U << 6U) //Digital loop back
| (uint32)((uint32)0U << 4U) //Start Byte
| (uint32)((uint32)1U << 3U) //Free Data Format
| (uint32)(I2C_8_BIT); //Bit Count

i2cREG1->IMR = (uint32)((uint32)0U << 6U) //Address as slave interrupt
| (uint32)((uint32)0U << 5U) //Stop Condition detect interrupt
| (uint32)((uint32)0U << 4U) //Transmit data ready interrupt
| (uint32)((uint32)0U << 3U) //Receive data ready interrupt
| (uint32)((uint32)0U << 2U) //Register Access ready interrupt
| (uint32)((uint32)0U << 1U) //No Acknowledgement interrupt
| (uint32)((uint32)0U); //Arbitration Lost interrupt

i2cREG1->DMACR = 0x00U;

i2cREG1->MDR |= (uint32)I2C_RESET_OUT;

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

After this the start condition is then set

i2cSetStart(i2cREG1);

Both SDA and SCL go to logic low

STR register reads 0x1010

Then the address & write bit for the FM24CL64B is sent

i2cSendByte(i2cREG1, 0xA8);

STR register reads 0x1410

Next, the address to start write from is sent

i2cSendByte(i2cREG1, 0x05);

STR register reads 0x1400

at which point the code understandably halts at

while ((i2c->STR & (uint32)I2C_TX_INT) == 0U){}

When sending 0xA8, my oscilloscope picks up the following:

where blue = SCL, yellow = SDA

Thoughts?

Cheers,

Alan

Hi,

From what I can see on the oscilloscope I believe I have got the I2C to transmit, however I can not check as the receive part is causing issues.

After i2cSetStop(i2cREG1); I have the following code

i2cSetStart(i2cREG1);
i2cSendByte(i2cREG1, 0xA9); //address of dut ((0x4) <<1) and read (1)
i2cSendByte(i2cREG1, 0x05); //read address
i2cSendByte(i2cREG1, 0x00); //read address
i2cREG1->MDR &= ~I2C_TRANSMITTER; //change to Receive mode
i2cstuff = i2cReceiveByte(i2cREG1);
i2cstuff = i2cReceiveByte(i2cREG1);
i2cSetStop(i2cREG1);

however it stops because RXRDY in STR is not 1

From the link you sent me it looks like it should be possible.

Setting I2C to receiver mode seems to set another start condition, is this correct?

During successive reads is it possible to leave the I2C inactive, carry out another process on the TMS570 and then continue on the I2C where I left off?

Cheers

Alan

Hi,

It seems the master is not setting the stop condition, both SDA and SCL stay low.

This is after calling i2cSetStop(i2cREG1);

Later on in the code I setup to receive data with

i2cREG1->MDR = (i2cREG1->MDR & ~I2C_TRANSMITTER) | I2C_RESET_OUT | I2C_STOP_COND | I2C_MASTER;

which produces MDR = 0x2C28;

with the line i2cstuff = i2cReceiveByte(i2cREG1);

I see this on the lines

but the code hangs at 

while ((i2c->STR & (uint32)I2C_RX_INT) == 0U)

as STR = 0x1010

Looking at it i would guess that the i2c module is out of sync and is instead transmitting the previous line

i2cSendByte(i2cREG1, 0xA9);

Why is i2c not issuing the stop condition and why is it out of sync?

Cheers,

Alan