| 0,0 → 1,57 |
|---|
| #include <msp430.h> |
| #include "defines.h" |
| #include "spi.h" |
| |
| int main(void) { |
| WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer |
| |
| /* --- Set Oscillator Settings (8Mhz) --------------- */ |
| // Set DCO to 5, MOD to 0 |
| DCOCTL = DCO2 | DCO0; |
| // Set RSEL to 13 |
| BCSCTL1 = RSEL3 | RSEL2 | RSEL0; |
| // MCLK = DCO/1, SMCLK = MCLK/8 |
| BCSCTL2 = SELM_0 | DIVM_0 | DIVS_3; |
| // LFXT1 = VLOCLK, 1pF termination |
| BCSCTL3 = LFXT1S_2 | XCAP_0; |
| // Disable oscillator fault interrupt |
| IE1 &= ~OFIE; |
| /* -------------------------------------------------- */ |
| |
| /* --- Set Port Settings ---------------------------- */ |
| // Set ports 1.5/1.6 as outputs |
| // Set remaining ports as inputs |
| P1DIR = BIT5 | BIT6; |
| P2DIR = 0x00; |
| // Enable pull-down resistors |
| P1REN = ~(BIT5 | BIT6); |
| P2REN = 0xFF; |
| // Set initial port values |
| P1OUT = 0x00; |
| P2OUT = 0x00; |
| /* -------------------------------------------------- */ |
| |
| /* --- Set USI Settings (SPI) ----------------------- */ |
| // Enable SDA/SCL/SCLK ports, MSB->LSB, master mode, output enabled |
| USICTL0 = USIPE7 | USIPE6 | USIPE5 | USIMST | USIOE; |
| // I2C disabled, counter interrupt enabled |
| USICTL1 = USIIE; |
| // SMCLK/1, SMCLK source, idle low |
| USICKCTL = USIDIV_0 | USISSEL_2; |
| // Enable USI module (clear reset bit) |
| USICTL0 &= ~USISWRST; |
| /* -------------------------------------------------- */ |
| |
| // Write 0 to the counter to trigger the USI interrupt |
| // USICNT = 0; |
| |
| // Go into low power mode with interrupts enabled |
| _BIS_SR(LPM0_bits + GIE); |
| } |
| |
| #pragma vector=USI_VECTOR |
| __interrupt void USI_SPI_Vector(void) { |
| char value = USISR; |
| USISR = 0xAB; |
| USICNT = 8; |
| } |