Hello,
I have two MSP430 Launchpads worrking as master and slave. The code usa for testing is simple: the master sends one byte and the slave echoes.
The master is sending properly, as I've verified it with the oscilloscope; the slave however sends the bits shifted a random number of bits left or rigth. The problem only happens when the system is working with UCCKPH=1. If not, it works perfectly with both reading and sending properly.
I've checked the errata on the MSP430G2553 and there is a bug related to UCCKPH, but I'm not sure whether it aplies to this, nor do I understand the proposed workaround.
Below is the code for the slave Laucnhpad.
Thanks,
Federico
#include <msp430.h>
/*
* main.c
*/
void main(void) {
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer
while (!(P1IN & BIT4));
P1SEL = BIT1 + BIT2 + BIT4 + BIT5;
P1SEL2 = BIT1 + BIT2 + BIT4 + BIT5;
UCA0CTL1 = UCSWRST;
UCA0CTL0 |= UCMSB + UCSYNC + UCMODE1 + UCCKPH;
UCA0CTL1 &= ~UCSWRST;
IE2 |= UCA0RXIE;
__bis_SR_register(GIE);
while(1);
}
// Echo character
#pragma vector=USCIAB0RX_VECTOR
__interrupt void USCI0RX_ISR (void)
{
while(1)
{
if(UCA0TXIFG)
{
UCA0TXBUF = UCA0RXBUF;
break;
}
}
}
