msp430g2x21 usi 02 asm

; MSP430G2x21/G2x31 Demo - SPI full-Duplex 3-wire Master ; ; Description: SPI Master communicates full-duplex with SPI Slave using ; 3-wire mode.. ; Master will pulse slave P1.2 which re

; MSP430G2x21/G2x31 Demo - SPI full-Duplex 3-wire Master

;

; Description: SPI Master communicates full-duplex with SPI Slave using

; 3-wire mode The level on P1.4 is TX'ed and RX'ed to P1.0

; Master will pulse slave P1.2 which resets USICNT counter for synch start

; ACLK = n/a, MCLK = SMCLK = Default DCO

; *******THIS IS MASTER CODE******

; Slave Master

; MSP430G2x21/G2x31 MSP430G2x21/G2x31

;

-; | /|\| XIN|-; | | | | |

; | |RST XOUT|-; | | /|\ | |

; | RST/NMI| +< |P1.2 |

; LED <-|P1.0 | | P1.4|<-; ->P1.4|<-;|P1.4 | | P1.0|->P1.4|<-; LED ; | SDI/P1.7|< -|P1.6/SDO |

; | SDO/P1.6| ->|P1.7/SDI |

; | SCLK/P1.5|< -|P1.5/SCLK |

; ; D Dang ; Texas Instruments Inc ; October 2010 ; Built with Code Composer Essentials Version: 4.2.0 ;****************************************************************************** .cdecls C,LIST, "msp430g2221.h"

text ; Program Start

; -RESET mov.w #0280h,SP ; Initialize stackpointer StopWDT mov.w #WDTPW+WDTHOLD,&WDTCTL ; Stop watchdog timer SetupP1 mov.b #010h,&P1OUT ; P1.4 set, else bis.b #010h,&P1REN ; P1.4 pullup bis.b #001h,&P1DIR ;

SetupUSI bis.b #USIPE7+USIPE6+USIPE5+USIMST+USIOE,&USICTL0; Port, SPI master bis.b #USIIE,&USICTL1 ; Counter interrupt, flag remains mov.b #USIDIV_4+USISSEL_2,&USICKCTL ; /16 SMCLK bic.b #USISWRST,&USICTL0 ; Enable USI mov.b &P1IN,&USISRL ; init-load TX data ResetSlave bis.b #004h,&P1DIR ; Reset Slave bic.b #004h,&P1DIR ;

clr.w R4 ; Delay for Slave Delay dec.w R4 ;

jnz Delay ;

mov.b #08h,&USICNT ; init-load counter, clear flag ;

Mainloop bis.b #LPM0+GIE,SR ; CPU off w/ interrupts enabled nop ; Required for debugger only ;

; -USI_ISR;

mov.b &USISRL,R4 ; Temp save RX'ed char mov.b &P1IN,&USISRL ;

bic.b #01h,&P1OUT ;

bit.b #010h,R4 ;

jnc L2 ;

L1 bis.b #01h,&P1OUT ;

L2 mov.b #08h,&USICNT ; re-load counter, clear flag

reti ; Exit ISR

;

; -; Interrupt Vectors

.sect ".reset" ; MSP430 RESET Vector

short RESET ;

sect ".int04" ; USI Vector

short USI_ISR ;

end