Hi all,
I am doing LCD interfacing using SSI0 communication (8 bit data) in Code Composer Studio Version 6.1.0.00104 .
However, my SSI0_DR_R always remain 0 for whatever value I write.
May I know what is the reason behind that have caused this problem?
For my case, Port A, B, D and E is used to interface with LCD, but I only list PortA function since it is related to SSI0.
void PortA_Init(void)
{
volatile unsigned long delay;
SYSCTL_RCGC2_R |= 0x00000001; // Enable clock to PORTA
delay = SYSCTL_RCGC2_R; // Delay
GPIO_PORTA_LOCK_R = 0x4C4F434B; // Unlock PortA
GPIO_PORTA_CR_R = 0xFC; // Allow changes for PA2-7
GPIO_PORTA_AMSEL_R = 0x00; // Disable analog function for PA2-7
GPIO_PORTA_PCTL_R = 0x00000000; // GPIO clear bit PCTL
GPIO_PORTA_DIR_R |= 0x7C; // Set PA2-6 output, PA7 input
GPIO_PORTA_AFSEL_R = 0x00; // Disable alternate function for PA2-7
GPIO_PORTA_PUR_R = 0x00; // Disable pullup resistors for PA2-7
GPIO_PORTA_DEN_R |= 0xFC; // Enable digital pins for PA2-7
}
void SSI0_PA2_Init(void)
{
SYSCTL_RCGCSSI_R |= 0x01; // Activate SSI0
SYSCTL_RCGCGPIO_R |= 0x01; // Activate Port A
while((SYSCTL_PRGPIO_R&0x0001) == 0){}; // Ready?
GPIO_PORTA_AFSEL_R |= 0x2C; // Enable alternate function on PA2,3,5
GPIO_PORTA_DEN_R |= 0x2C; // Enable digital I/O on PA2,3,5
GPIO_PORTA_PCTL_R &= ~0x00F0FF00; // Configure PA2 as SSI0Clk, PA3 as SSI0Fss
GPIO_PORTA_PCTL_R |= 0x00202200; // Configure PA5 as SSI0Tx
GPIO_PORTA_AMSEL_R = 0x00; // Disable analog function for PA2-7
SSI0_CR1_R &= ~0x02; // Disable SSI
SSI0_CR1_R &= ~0x04; // Master mode
SSI0_CPSR_R = 0x02; // CPSDVSR = 2
SSI0_CR0_R |= 0x0F07; // SCR = 16, SPH = 0, SPO = 0, FRF = Freescale format, 8-bit data
SSI0_DR_R = 0x0000; // Load 0 into transmit FIFO
SSI0_CR1_R |= 0x02; // Enable SSI
}
void SSI0_SendReceiveData8(uint8_t data)
{
while((SSI0_SR_R&0x02)==0){}; // Wait until room in Transmit FIFO is not full
SSI0_DR_R = data; // Send data out (Need to check whether need to shift data)
}
