HCS08QG8 - IIC Read - Codewarrior Simulation

FC — Tue, 01 Jun 2010 01:44:03 GMT

Hello all,

I searched the 8 bit and 8 bit Codewarrior forums, but did find a similar post.

Currently, I am working on a test program to read al byte from the Microchip 23008 port expander. No actual use of data, but only a test. I have USB oscilloscope on order to see the IIC bus. In the mean time, I am using the Codewarrior simulator to view the IIC bus transfer. See the code below. My question relates to the second byte received. Is there actually a second byte received ?

Thanks

void DISPReadBarGraphData(void)
{

unsigned char dout;
unsigned char acknowledge;

SEND_START_BIT;         // send start signal
IICD = DISP_MCP_1_SL_ADDR;   // send MCP control byte (R\W bit preset to 0)
while(!IICS_IICIF);     // wait for byte transfer to complete
IICS_IICIF = 0;
acknowledge = check_ACK();
if (acknowledge == DEVICE_NO_ACK)
    return;
IICD = DISP_OLAT;       // send MCP OLAT register address
while(!IICS_IICIF);     // wait for byte transfer to complete
IICS_IICIF = 0;
acknowledge = check_ACK();
if (acknowledge == DEVICE_NO_ACK)
    return;
SEND_RPSTART_BIT;       // send repeat start bit
IICD = DISP_MCP_1_SL_ADDR | 0x01;    // send MCP control byte (R\W bit set to 1
while(!IICS_IICIF); // wait for byte transfer to complete
IICS_IICIF = 0;
acknowledge = check_ACK();
if (acknowledge == DEVICE_NO_ACK)
    return;
IIC_RX_MODE;            // set IIC for recieve mode
IICC_TXAK = 1;      // no ACK sent to slave
dout = IICD;        // dummy read to clock byte in
while(!IICS_IICIF); // wait for byte transfer to complete
IICS_IICIF = 0;
SEND_STOP_BIT;
dout = IICD;
DISPGraphContent = dout;
  }

Re: HCS08QG8 - IIC Read - Codewarrior Simulation

xmas — Thu, 03 Jun 2010 23:38:54 GMT

Hi,

I have not an answer to your question neither a solution but a similar problem.

My implementation looks equal:

void IIC_Init(void)
{
// clear control and status register
IIC1C = 0;
IIC1S = 0;

IIC1C_IICEN   = 1; // Enable I2C;
IIC1C_TXAK    = 1; // not generate ACK by master after transfer;
IIC1C_MST     = 1; // Master mode actually; Generates a start signal
IIC1C_TX      = 1; // Master is transmitting
IIC1F         = 0x40;   // mult = 1, ICR = 0;
}

and my read looks like:

byte IIC_readFirst_byte(byte addr)
{
byte temp;
temp = addr << 1;

if(!IIC1C_MST)
    IIC1C_MST = 1;

IIC1C_TXAK = 0; // RX/TX = 1; MS/SL = 1; TXAK = 0;
IIC1C |= 0x30; // And generate START condition;

IIC1D = temp; // Address the slave and set up for master transmit;

while(!IIC1S_IICIF);     // wait for byte transfer to complete
IIC1S_IICIF = 0;

while(IIC1S_RXAK); // check for RXAK;
   //-----Slave ACK occurred------------
      IIC1C_RSTA = 1; // set up repeated start;

IIC1D = 1; // read flag 1?

while(!IIC1S_IICIF);     // wait for byte transfer to complete
IIC1S_IICIF = 0;

   while (IIC1S_RXAK); // check for RXAK;
   //-----Slave ACK occurred------------
   IIC1C_TX = 0; // set up to receive;

   // dummy read
   RD_data = IIC1D;

   while(!IIC1S_IICIF);     // wait for byte transfer to complete
   IIC1S_IICIF = 0;

   IIC1C_TXAK = 0; // want to read more;

return RD_data;
}

I do the reading then in an other function call because the data I want to receive

needs some time to be ready for transfer.

I do not get some "usable" data out of the I^2 bus and I do not know why.

I send the address of the slave out on the bus and afterwards I send the 1 for the

slave to write now, but I have found 2 astonishing surprises:

1. After I send the address of the slave the SDA line moves up after ack of the slave

has arrived! Is this normal???

2. When I do not do the step by step debugging I can see on the oszi that after

sending out the address of the slave, the restart routin is called and then not the 1

that I send afterwards is on the bus no, it is a 0xff! I have no glue where this comes from.

Do you know what is going on on the bus?

I do not really understand the information of the jpeg you have send with.

Maybe finding togehter a solution for both problems?

Greetings,

xmas

topic Re: HCS08QG8 - IIC Read - Codewarrior Simulation in 8-bit Microcontrollers

HCS08QG8 - IIC Read - Codewarrior Simulation

Re: HCS08QG8 - IIC Read - Codewarrior Simulation