Dang // Texas Instruments Inc.
Trang 1//****************************************************************************** // MSP430G2xx2 Demo - USI SPI Interface with HC165/164 Shift Registers
//
// Description: Demonstrate USI in two-way SPI mode Data are read from
// an HC165, and same data written back to the HC164
// ACLK = n/a MCLK = SMCLK = default DCO, USICLK = SMCLK/2
// //*USART0 control bits are in different SFR's from other MSP430's//
//
// MSP430G2xx2
//
-// /|\| XIN|-// | | | ^ HC164 // HC165 |RST XOUT|- |
-// - | | |-|/CLR,B | 8
// 8 | /LD|< -|P1.1 SIMO0/P1.6| ->|A Qx| \-> // -\->|A-H CLK|< -|P1.5/SCLK0 - P1.5| ->|CLK |
// |-|INH QH| ->|P1.7/SOMI0 | | |
// |-|SER | | | | |
// - | | | | | |
//
// D Dang
// Texas Instruments Inc
// December 2010
// Built with CCS Version 4.2.0 and IAR Embedded Workbench Version: 5.10
//******************************************************************************
#include <msp430g2452.h>
void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1OUT = 0;
P1OUT |= 0x02;
P1DIR |= 0x02;
USICTL0 |= USIPE7 + USIPE6 + USIPE5 + USIMST + USIOE; // Port, SPI Master USICTL1 |= USICKPH + USIIE; // Counter interrupt, flag remains set
USICKCTL = USIDIV_1 + USISSEL_2; // /2 SMCLK
USICTL0 &= ~USISWRST; // USI released for operation
USICNT = 8; // init-load counter
while (1) // Loop
{
unsigned i;
for (i = 0xFFFF; i > 0; i ); // Delay
while (!(USIIFG & USICTL1)); // Counter clear?
P1OUT &= ~0x02; // Latch data into 'HC165
P1OUT |= 0x02;
// ******************** // Read data are ready to be written USICNT = 8; // re-load counter
}
}