Hello
I am able to generate clock and data using the following code. However the chip-select is not triggered or asserted automatically. I believe I am missing something, can anyone point out.
Initialization Code:
SPISelectPtr = SPI0_BASE_PTR;
// Turn on the clock
SIM_SCGC6 |= SIM_SCGC6_DSPI0_MASK;
// Select pins
// Clock
PORTC_PCR5 &= (~PORT_PCR_MUX_MASK);
PORTC_PCR5 = PORT_PCR_MUX(2) | PORT_PCR_DSE_MASK | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK;
// Sout
PORTC_PCR6 &= (~PORT_PCR_MUX_MASK);
PORTC_PCR6 = PORT_PCR_MUX(2) | PORT_PCR_DSE_MASK | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK;
// Sin
PORTC_PCR7 &= (~PORT_PCR_MUX_MASK);
PORTC_PCR7 = PORT_PCR_MUX(2) | PORT_PCR_DSE_MASK | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK;
//Chip Select 0
PORTD_PCR0 &= (~PORT_PCR_MUX_MASK);
PORTD_PCR0 = PORT_PCR_MUX(2) | PORT_PCR_DSE_MASK | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK;;
PORTD_PCR4 &= (~PORT_PCR_MUX_MASK);
PORTD_PCR4 = PORT_PCR_MUX(2) | PORT_PCR_DSE_MASK | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK;;
// Select Master Mode
// Continous Clock is disabled
// FRZ is disabled, can be enabled later using SPI_MCR_FRZ_MASK
SPI_MCR_REG(SPISelectPtr) = (SPI_MCR_DCONF(0) | SPI_MCR_MSTR_MASK | SPI_MCR_PCSIS(0) | SPI_MCR_PCSIS(1) | SPI_MCR_PCSIS(2)
| SPI_MCR_CLR_TXF_MASK | SPI_MCR_CLR_RXF_MASK);
// Frame Size = 8
// CPOL = 1
// CPHA = 1
// Delay after Transfer Prescaler value is 5
// Baud Rate Prescaler value is 1
SPI_CTAR_REG(SPISelectPtr, 0) = SPI_CTAR_FMSZ(8) | SPI_CTAR_CPOL_MASK | SPI_CTAR_CPHA_MASK | SPI_CTAR_PDT(2) | SPI_CTAR_BR(6);
Test Function to call byte write
void vTestWriteByteToSPI(uint8_t u8Data, uint8_t chip_select)
{
SPI_MemMapPtr SPISelectPtr = SPI0_BASE_PTR;
// Making sure no chip select beyond 0 and 1
chip_select &= 1;
// Write a byte with CS0
SPI_PUSHR_REG(SPISelectPtr) = SPI_PUSHR_TXDATA(u8Data) | SPI_PUSHR_CONT_MASK | SPI_PUSHR_CTAS(0) | SPI_PUSHR_PCS(chip_select + 1);
// Wait Until Read Flag
while (!( SPI_SR_REG(SPISelectPtr) & SPI_SR_RFDF_MASK ));
// Clear Read Flag
SPI_SR_REG(SPISelectPtr) |= SPI_SR_RFDF_MASK;
}
I am using Freescale ARM Compiler, CodeWarrior 10.4. There are pull ups on the board for CS pins. Please help pointing out mistake if any.
