//****************************************************************************** // MSP430G2x21/G2x31 Demo - USI SPI Interface to TLC549 8-bit ADC
//
// Description: This program demonstrates the USI in SPI mode interface to a // TLC549 8-bit ADC If AIN > 0.5(REF+ - REF-), P1.0 set, else reset
// ACLK = n/a, MCLK = SMCLK = default DCO, UCICLK = SMCLK/4
// //** VCC must be at least 3v for TLC549 **//
//
// MSP430G2x21/G2x31
//
-// /|\|
XIN|-// TLC549 | | |
// - |RST
XOUT|-// | CS|< -|P1.1 |
// | DATAOUT| ->|P1.7/SOMI P1.0| >LED
// ~>|AIN I/O CLK|< -|P1.5/SCLK |
//
// D Dang
// Texas Instruments Inc
// October 2010
// Built with CCS Version 4.2.0 and IAR Embedded Workbench Version: 5.10
//******************************************************************************
#include <msp430g2221.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
}