First try to create a TWIM driver from scratch without any DMA. Following the steps in the OPS I get mixed behavior and only the chapter with DMA generates any clock and data on the interface. Without setting Master enable bit nothing will start and there is no reference in the non DMA flow diagram. Anyhow when using Master bit I get all TXD data on the bus but not RXD.
I use Prev-DK board with SDOF Stick connected to P0.27/P0.26 at 100kHz.
This is my flow right now:
// ***** INIT *****
#define USED_I2C_BLOCK 0x40003000
output_32( USED_I2C_BLOCK+I2C_TXD_MAXCNT_REG, 2 );
// enable master mode
output_32( USED_I2C_BLOCK+I2C_ENABLE_REG, 1 );
// ***** TRANSMITT *****
// send start condition
output_32( USED_I2C_BLOCK+I2C_STARTTX_REG, 1 );
// wait for int
// write data (slave address)
output_32( USED_I2C_BLOCK+I2C_TXD_REG, (SlaveAddress<<1) );
// wait for int
// write data (register address)
output_32( USED_I2C_BLOCK+I2C_TXD_REG, RegAddr );
// wait for int
// send stop bit
output_32( USED_I2C_BLOCK+I2C_STOP_REG, 1 );
// wait for int
// ***** RECEIVE *****
output_32( USED_I2C_BLOCK+I2C_RXD_MAXCNT_REG, DataBufferSize );
// enable master mode
output_32( USED_I2C_BLOCK+I2C_ENABLE_REG, 1 );
// send start condition
output_32( USED_I2C_BLOCK+I2C_STARTRX_REG, 1 );
// wait for int
// send read slave address
output_32( USED_I2C_BLOCK+I2C_TXD_REG, (SlaveAddress<<1)+1 );
// wait for int
while ( DataBufferSize-- )
{
if ( DataBufferSize == 0 )
{
// send stop bit
output_32( USED_I2C_BLOCK+I2C_STOP_REG, 1 );
}
// wait for int
// read data
*DataByte++ = input_32( USED_I2C_BLOCK+I2C_RXD_REG );
}
