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2019-11-12 23:43:53 +02:00

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; --COPYRIGHT--,BSD_EX
; Copyright (c) 2012, Texas Instruments Incorporated
; All rights reserved.
;
; Redistribution and use in source and binary forms, with or without
; modification, are permitted provided that the following conditions
; are met:
;
; * Redistributions of source code must retain the above copyright
; notice, this list of conditions and the following disclaimer.
;
; * Redistributions in binary form must reproduce the above copyright
; notice, this list of conditions and the following disclaimer in the
; documentation and/or other materials provided with the distribution.
;
; * Neither the name of Texas Instruments Incorporated nor the names of
; its contributors may be used to endorse or promote products derived
; from this software without specific prior written permission.
;
; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
; THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
; PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
; CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
; EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
; PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
; WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
; OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
; EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;
; ******************************************************************************
;
; MSP430 CODE EXAMPLE DISCLAIMER
;
; MSP430 code examples are self-contained low-level programs that typically
; demonstrate a single peripheral function or device feature in a highly
; concise manner. For this the code may rely on the device's power-on default
; register values and settings such as the clock configuration and care must
; be taken when combining code from several examples to avoid potential side
; effects. Also see www.ti.com/grace for a GUI- and www.ti.com/msp430ware
; for an API functional library-approach to peripheral configuration.
;
; --/COPYRIGHT--
;******************************************************************************
; MSP430F20x2/3 Demo - SPI full-Duplex 3-wire Slave
;
; 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 reset for synch start.
; ACLK = n/a, MCLK = SMCLK = Default DCO
;
; Slave Master
; MSP430F20x2/3 MSP430F20x2/3
; ----------------- -----------------
; | XIN|- /|\| XIN|-
; | | | | |
; | XOUT|- --|RST XOUT|-
; | | /|\ | |
; | RST/NMI|--+<----|P1.2 |
; LED <-|P1.0 | | P1.4|<-
; ->|P1.4 | | P1.0|-> LED
; | SDI/P1.7|<-------|P1.6/SDO |
; | SDO/P1.6|------->|P1.7/SDI |
; | SCLK/P1.5|<-------|P1.5/SCLK |
;
; P.Thanigai
; Texas Instruments Inc.
; May 2007
; Built with Code Composer Essentials Version: 2.0
;******************************************************************************
.cdecls C,LIST, "msp430.h"
;-------------------------------------------------------------------------------
.def RESET ; Export program entry-point to
; make it known to linker.
;------------------------------------------------------------------------------
.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+USIOE,&USICTL0; Port, SPI slave
bis.b #USIIE,&USICTL1 ; Counter interrupt, flag remains
bic.b #USISWRST,&USICTL0 ; Enable USI
mov.b &P1IN,&USISRL ; init-load TX data
mov.b #08h,&USICNT ; init-load counter, clear flag
;
Mainloop bis.b #LPM4+GIE,SR ; LPM4 w/ interrupts enabled
nop ; Required for debugger only
;
;------------------------------------------------------------------------------
USI_ISR;
;------------------------------------------------------------------------------
mov.b &USISRL,R4 ; Temp save RX'ed char
mov.b &P1IN,&USISRL ;
mov.b #08h,&USICNT ; re-load counter, clear flag
bic.b #01h,&P1OUT ;
bit.b #010h,R4 ;
jnc L2 ;
L1 bis.b #01h,&P1OUT ;
L2 reti ; Exit ISR
;
;------------------------------------------------------------------------------
; Interrupt Vectors
;------------------------------------------------------------------------------
.sect ".reset" ; MSP430 RESET Vector
.short RESET ;
.sect ".int04" ; USI Vector
.short USI_ISR ;
.end