MSP430G2 SPI 16bit configuration

Nistor Daniel

Hello,

I try to use Launchpad to comunicate with an external DAC on USCIB SPI_BUS.

But I do not have enough information how I can configure the SPI for my requirements.

I have configure 3 wire SPI with SLCK=1MHZ and 16bit data. Is there a example or documentation regarding the SPI registers?

I foun the code but only with 8 bit data;

P1SEL = BIT1 + BIT2 + BIT4;

P1SEL2 = BIT1 + BIT2 + BIT4;

UCA0CTL1 = UCSWRST; // **Put state machine in reset**

UCA0CTL0 |= UCCKPL + UCMSB + UCSYNC; // 3-pin, 8-bit SPI master

UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**

I will apreciate any help.

over 13 years ago

0 kazola over 13 years ago

Guru 18545 points

Yeah! There are many!

Are you using CCS5? You can get examples in the TI resource explorer.

This is the sample code msp430g2xx2_usi_05, for example ;)

#include <msp430g2452.h>

void main(void)
{
 WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer
 P1OUT = 0;
 P1DIR |= 0x03;
 USICTL0 |= USIPE7 + USIPE5 + USIMST + USIOE; // Port, SPI master
 USICTL1 |= USIIE; // Counter interrupt, flag remains set
 USICKCTL = USIDIV_2 + USISSEL_2; // /4 SMCLK
 USICTL0 &= ~USISWRST; // USI released for operation
 USICNT = 8; // init-load counter
 _BIS_SR(LPM0_bits + GIE); // Enter LPM0 w/ interrupt
}

// USI interrupt service routine
#pragma vector=USI_VECTOR
__interrupt void universal_serial_interface(void)
{
 P1OUT |= 0x02; // Disable TLC549
 if (USISRL > 0x7F)
 P1OUT |= 0x01;
 else
 P1OUT &= ~0x01;
 P1OUT &= ~0x02; // Enable TLC549
 USICNT = 8; // re-load counter
}

If not using CCS5, you can download examples from here:

http://www.ti.com/lsds/ti/microcontroller/16-bit_msp430/code.page?DCMP=MSP430&HQS=Other+OT+msp430codeexamples

Find your chip, get the zip with the examples, read the README within the zip to see the names of the correct examples, and choose the SPI example (I think there are 6) more similar to your question.

Good luck!

PS: You have more documentation here:

http://www.ti.com/lit/ug/slau144i/slau144i.pdf

And in docs like these:

http://www.ti.com/lit/ds/symlink/msp430g2152.pdf