Problem: configuring SSI direct register access
Hello to everyone
The Peripheral driver library defines two methodologies for accessing the microcontroller, these are the direct register access model (using the lm3sXXXX.h file)and the software driver model.
By implementing the register access model (and using as main template the blinky.c program) I did not succeed to send data. Notice: during the debugging, the respective registers except the data register are working fine. If anyone has a suggestion, then my code is here:
#include "lm3s1968.h"
int main(void)
{
/*Configure Clock configuration for 50MHz*/
SYSCTL_RCC_R = 0x01C00380;
/*0. Enable port A (SPI)
*/
SYSCTL_RCGC2_R = SYSCTL_RCGC2_GPIOA;
/*1. Configure input/output
*/
GPIO_PORTA_DIR_R = 0x2C;
/*2. Enable P(in)A SPI pins
*/
GPIO_PORTA_DEN_R = 0x3C;
/*3. Enable the peripheral clock of SSI
*/
SYSCTL_RCGC1_R = SYSCTL_RCGC1_SSI0;
/*4. Configure role as master
*/
SSI0_CR1_R = 0x00000000;
/*5. SSI Clock prescale register: Will run at 2MHz
*/
SSI0_CPSR_R = 0x00000005;
/*6. Configure protocol and clock: 4 is SRC, 1100 = C means mode 3, SPI, F means 16 bit
*/
SSI0_CR0_R = 0x000004CF;
/*7. Enable SSI
*/
SSI0_CR1_R = 0x00000002;
while(1)
{
/*8. Send message to FIFO Tx continuasly until
judgement day or if you unplug the hardware
*/
SSI0_DR_R = 0x183F;
}
return 0;
}
@LMI guys: It is a little bit of a pity that there is only the blinky example in this methodology (Direct register access). Would be possible some other examples in the future?
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