📄 fet140_dma_03.asm
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;******************************************************************************
; MSP-FET430P140 Demo - DMA0, Repeated Block UART1 9600, TACCR2, ACLK
;
; Description: DMA0 is used to transfer a string byte-by-byte as a repeating
; block to U1TXBUF. Timer_A operates continuously at 32768Hz with CCR2IFG
; triggering DMA0. "Hello World" is TX'd via 9600 baud UART1.
; ACLK= TACLK 32768Hz, MCLK= SMCLK= default DCO ~ 800k
; Baud rate divider with 32768Hz XTAL @9600 = 32768Hz/9600 = 3.41 (000Dh 4Ah )
; //* An external watch crystal on XIN XOUT is required for ACLK *//
; //* MSP430F169 Device Required *//
;
; MSP430F169
; -----------------
; /|\| XIN|-
; | | | 32768Hz
; --|RST XOUT|-
; | |
; | P3.6|------------> "Hello World"
; | | 9600 - 8N1
;
LF .equ 0ah ; ASCII Line Feed
CR .equ 0dh ; ASCII Carriage Return
Delta .equ 256 ; Delta = (target DCO)/(4096) = 1048576
;
; M. Buccini / L. Westlund
; Texas Instruments Inc.
; May 2005
; Built with Code Composer Essentials Version: 1.0
;******************************************************************************
.cdecls C,LIST, "msp430x16x.h"
;------------------------------------------------------------------------------
.text ; Progam Start
;------------------------------------------------------------------------------
RESET mov.w #0A00h,SP ; Initialize stackpointer
StopWDT mov.w #WDTPW+WDTHOLD,&WDTCTL ; Stop WDT
SetupP3 bis.b #0C0h,&P3SEL ; P3.6,7 = USART1 TXD/RXD
SetupUART0 bis.b #UTXE1+URXE1,&ME2 ; Enable USART1 TXD/RXD
bis.b #CHAR,&UCTL1 ; 8-bit characters
mov.b #SSEL0,&UTCTL1 ; UCLK = ACLK
mov.b #003h,&UBR01 ; 32k/9600=3.41
mov.b #000h,&UBR11 ;
mov.b #04Ah,&UMCTL1 ; no modulation
bic.b #SWRST,&UCTL1 ; **Initialize USART state machine**
SetupDMA0 mov.w #DMA0TSEL_1,&DMACTL0 ; CCR2 trigger
mov.w #String1,&DMA0SA ; Source block address
mov.w #TXBUF1,&DMA0DA ; Destination single address
mov.w #13,&DMA0SZ ; Block size
mov.w #DMADT_4+DMASRCINCR_3+DMASBDB+DMAEN,&DMA0CTL; Repeat, inc src
SetupTA mov.w #8192,&TACCR0 ; Char freq = TACLK/CCR0
mov.w #01,&TACCR2 ; DMA0 trigger
mov.w #TASSEL_1+MC_1,&TACTL ; ACLK, up-mode
;
Mainloop bis.w #LPM3,SR ; Enter LPM3
nop ; Required only for debugger
;
String1 .string CR,LF, "Hello World"
;
;-----------------------------------------------------------------------------
; Interrupt Vectors
;-----------------------------------------------------------------------------
.sect ".reset" ; MSP430 RESET Vector
.short RESET ;
.end
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