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#include "driver/spi.h"
#include <msp430.h>
signed char SPI::setup()
{
/* UCB0CLK Pin 2.2 */
P2SEL0 &= ~BIT2;
P2SEL1 |= BIT2;
P2DIR |= BIT2;
/* UCB0SIMO Pin 1.6 */
P1SEL0 &= ~BIT6;
P1SEL1 |= BIT6;
P1DIR |= BIT6;
/* UCB0SOMI Pin 1.7 */
P1SEL0 &= ~BIT7;
P1SEL1 |= BIT7;
P1DIR &= ~BIT7;
//P1REN |= BIT6;
UCB0CTLW0 = UCCKPH | UCMSB | UCMST | UCSYNC | UCMODE_0 | UCSSEL__SMCLK | UCSWRST;
UCB0BRW = 15; // /16 -> 1MHz
UCB0CTLW0 &= ~UCSWRST;
}
signed char SPI::xmit(unsigned char tx_len, unsigned char *tx_buf,
unsigned char rx_len, unsigned char *rx_buf)
{
volatile char rxbuf_cache;
if (tx_len < 1) {
return -1;
}
UCB0IE &= ~(UCTXIE | UCRXIE);
while (UCB0STATW & UCBUSY) ;
rxbuf_cache = UCB0RXBUF;
UCB0TXBUF = tx_buf[0];
unsigned char tx_pos = 1;
unsigned char rx_pos = 0;
while (tx_pos < tx_len || rx_pos < rx_len) {
if ((tx_pos < tx_len) && (UCB0IFG & UCTXIFG)) {
UCB0TXBUF = tx_buf[tx_pos++];
}
if (UCB0IFG & UCRXIFG) {
if (rx_pos < rx_len) {
rx_buf[rx_pos] = UCB0RXBUF;
} else {
rxbuf_cache = UCB0RXBUF;
}
rx_pos++;
}
}
}