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#include "driver/spi.h"
#include <msp430.h>
signed char SPI::setup()
{
/* UCA1CLK Pin 2.4 */
P2SEL0 &= ~BIT4;
P2SEL1 |= BIT4;
P2DIR |= BIT4;
/* UCA1SIMO Pin 2.5 */
P2SEL0 &= ~BIT5;
P2SEL1 |= BIT5;
P2DIR |= BIT5;
/* UCA1SOMI Pin 2.6 */
P2SEL0 &= ~BIT6;
P2SEL1 |= BIT6;
P2DIR &= ~BIT6;
//P2REN |= BIT6;
UCA1CTLW0 |= UCSWRST;
UCA1MCTLW = 0; // no modulation
UCA1CTLW0 = UCCKPH | UCMSB | UCMST | UCSYNC | UCMODE_0 | UCSSEL__SMCLK | UCSWRST;
UCA1BRW = 15; // /16 -> 1MHz
UCA1CTLW0 &= ~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;
}
UCA1IE &= ~(UCTXIE | UCRXIE);
while (UCA1STATW & UCBUSY) ;
rxbuf_cache = UCA1RXBUF;
UCA1TXBUF = 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) && (UCA1IF & UCTXIFG)) {
UCBA1TXBUF = tx_buf[tx_pos++];
}
if (UCA1IFG & UCRXIFG) {
if (rx_pos < rx_len) {
rx_buf[rx_pos] = UCA1RXBUF;
} else {
rxbuf_cache = UCA1RXBUF;
}
}
rx_pos++;
}
}
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