棒极了,我上次有release的帮忙汇编实验成功了.
下面是汇编程序,供大家参考!!
;主要函数及其功能:1."Set_DCO"校准(Calibrate) DCO
; 2."TA0_ISR" TIME_A中断子程序
; 3."RX_Ready"准备接收UART ready to RX one Byte
; 4."TX_Byte"发送接收到的一个字节
;备注:可用串口调试助手2.2测试
;******************************************************************************
;说明: 发送1个字节,接收1个字节,格式:TX:"01",RX:"01"
; This program demonstrates a half-duplex 9600-baud UART using
; Timer_A3 and a 32kHz crystal. The program will wait in LPM3, echoing back
; a received character using 8N1 protocol. The Set_DCO subroutine will
; calibrate the DCOCLK to ~2Mhz, which is used as the Timer_A clock.
; ACLK = LFXT1/8 = 32768/8, MCLK = SMCLK = target DCO
; //*External watch crystal installed on XIN XOUT is required for ACLK*//
;
; MSP430F1121
; -----------------
; /|\| XIN|-
; | | | 32k
; --|RST XOUT|-
; | |
; | CCI0A/TXD/P1.1|-------->
; | | 9600 8N1
; | CCI0B/RXD/P2.2|<--------
;-------------------------------------------------------------
; CPU registers used
#define RXTXData R4
#define BitCnt R5
;Conditions for 9600 Baud HW/SW UART, SMCLK = DCOCLK ~ 2Mhz
Bitime_5 equ 0104 ; ~ 0.5 bit length
Bitime equ 0208 ; ~ 9615 baud
Delta equ 0488 ; DCOCLK = (Delta)/(32768/8)
RXD set 004h ; RXD on P2.2
TXD set 002h ; TXD on P1.1
;
; M.Buccini
; Texas Instruments, Inc
; January 2004
;******************************************************************************
#include "msp430x11x1.h"
;------------------------------------------------------------------------------
ORG 0FC00h ; Program Start
;------------------------------------------------------------------------------
RESET mov.w #300h,SP ; Initialize Stackpointer
StopWDT mov.w #WDTPW+WDTHOLD,&WDTCTL ; Stop WDT
SetupBC bis.b #DIVA_3,&BCSCTL1 ; ACLK=LFXT1CLK/8=4096
Setup_TA mov.w #TASSEL_2+MC_2,&TACTL ; Timer_A输入信号为SMCLK, 连续增计数0H->0FFFFH->0H->0FFFFH
call #Set_DCO ; 校准(Calibrate) DCO
SetupC0 mov.w #OUT,&CCTL0 ; TXD Idle as Mark
SetupP1_2 bis.b #TXD,&P1SEL ; P1.1/TA0 for TXD function
bis.b #TXD,&P1DIR ; TXD output on P1
bis.b #RXD,&P2SEL ; P2.2/TA0 as RXD input
;
Mainloop call #RX_Ready ; 准备接收UART ready to RX one Byte
bis.w #LPM3+GIE,SR ; Enter LPM3 w/ int until Byte RXed
call #TX_Byte ; 发送接收到的一个字节TX Back RXed Byte Received
jmp Mainloop ;
;
;-----------------------------------------------------------------------------
TX_Byte ; Subroutine that Transmit One Byte from RXTXData Buffer.
;-----------------------------------------------------------------------------
bis.b #04h,&P1DIR ;打开端口方向
bis.b #04h,&P1OUT ;定义使能端
mov.w &TAR,&CCR0 ; TA定时器值送CCR0(Current state of TA Counter)
add.w #Bitime,&CCR0 ; 加一个位时间(Some time till first bit)
bis.w #0100h, RXTXData ; 置停止位Add mark stop bit to RXTXData
rla.w RXTXData ; 算术左移Add space start bit
mov.w #10,BitCnt ; 10位Load Bit Counter, 8data + ST/SP
mov.w #OUTMOD0+CCIE,&CCTL0 ; 输出模式，允许中断TXD = mark = idle
TX_Wait bit.w #CCIE,&CCTL0 ; 等待发送完成Wait for TX completion
jnz TX_Wait ;
ret ;
;
;-----------------------------------------------------------------------------
RX_Ready ; Subroutine that will Receive One Byte into RXTXData Buffer.
; !! Sync capture not possible as DCO=TACLK=SMCLK can be off !!
;-----------------------------------------------------------------------------
bis.b #08h,&P1DIR ;打开端口方向
bic.b #08h,&P1OUT ;定义使能端
mov.w #08,BitCnt ; Load Bit Counter, 8 data bits
SetupRX mov.w #CM1+CCIS0+OUTMOD0+CAP+CCIE,&CCTL0 ;上升沿捕获,选择CCI0A为捕获的输入信号源,
;输出模式,捕获模式,允许中断(Neg Edge,Cap)
ret ;
;
;-----------------------------------------------------------------------------
TA0_ISR ; CCR0/UART ISR: RXTXData Buffer holds UART Data.
;-----------------------------------------------------------------------------
add.w #Bitime,&CCR0 ; 1个位时间Time to Next Bit
bit.w #CCIS0,&CCTL0 ; RX on ISCCIB?
jnz UART_RX ; 为1跳(即选择CCI0B为捕获的输入信号源)Jump --> RX
; 为0(即选择CCI0A为捕获的输入信号源)
UART_TX cmp.w #00h,BitCnt ; 10为是否发完
jne TX_Next ; 未完跳Next bit?
bic.w #CCIE,&CCTL0 ; 完了清除中断All Bits TX or RX, Disable Int.
reti ;
TX_Next bic.w #OUTMOD2,&CCTL0 ; 清除TX Mark
rra.w RXTXData ; 算术右移LSB is shifted to carry
jc TX_Test ; 为1跳Jump --> bit = 1
TX_Space bis.w #OUTMOD2,&CCTL0 ; 为0 PWM翻转/复位TX Space
TX_Test dec.w BitCnt ; 位计数减1位All bits sent (or received)?
reti ;
;
UART_RX bit.w #CAP,&CCTL0 ; 是否为捕获模式Compare mode for start bit edge
jz RX_Bit ; 不是跳Start bit edge?
RX_Edge bic.w #CAP,&CCTL0 ; 是,清除捕获模式Switch to Compare mode
add.w #Bitime_5,&CCR0 ; 加半位时间First databit 1.5 bits from edge
mov.w #CPUOFF+GIE,0(SP) ; !!! DCO needs to remain on !!!
reti ;
RX_Bit bit.w #SCCI,&CCTL0 ; 为1时C=1,为0时C=0,Get bit waiting in receive latch
rrc.b RXTXData ; 带进位右移Store received bit
RX_Test dec.w BitCnt ; 位计数减1 All bits sent (or received)?
jnz RX_Next ; 不位0继续接收Next bit?
;>>>>>>>>>> Decode of Received Byte Here <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
RX_Comp bic.w #CCIE,&CCTL0 ; 为0清除中断使能All Bits RXed, Disable Interrupt
mov.w #GIE,0(SP) ; Decode Byte= Active in Mainloop
;>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
RX_Next reti ;
;
;-----------------------------------------------------------------------------
Set_DCO; Subroutine: Sets DCO to selected frequency based on Delta.
; R14 and R15 are used, ACLK = 32768/8 Timer_A clocked by DCOCLK
;-----------------------------------------------------------------------------
clr.w R15 ;
Setup_CC2 mov.w #CM_1+CCIS_1+CAP,&CCTL2 ; 上升沿捕获，选择CCI2B为捕获的输入信号源，选择捕获模式
Test_DCO bit.w #CCIFG,&CCTL2 ; Test 捕获（capture） flag
jz Test_DCO ; 未捕获继续查
bic.w #CCIFG,&CCTL2 ; Clear capture flag
;
AdjDCO mov.w &CCR2,R14 ; R14 = captured SMCLK
sub.w R15,R14 ; R14 = capture difference，R14=R14-R15
mov.w &CCR2,R15 ; R15 = captured SMCLK
cmp.w #Delta,R14 ; Delta（488） = SMCLK/(32768/8)
jlo IncDCO ; R14<488跳
jeq DoneDCO ; R14=488跳
DecDCO dec.b &DCOCTL ; DCOCTL=DCOCTL-1(Slow DCO with DCO and MOD)
jnz Test_DCO ; |=0跳(Slower?)
cmp.b #XT2OFF+DIVA_3,&BCSCTL1 ; Can RSEL.x be decremented?
jz DoneDCO ; 相等返回(jmp>DCO at slowest setting)
dec.b &BCSCTL1 ; BCSCTL1=BCSCTL1-1(Decrement RSEL.x)
jmp Test_DCO ; 跳
IncDCO inc.b &DCOCTL ; DCOCTL=DCOCTL+1(Speed DCO with DCO and MOD)
jnc Test_DCO ; 没有溢出跳(Faster?)
cmp.b #XT2OFF+DIVA_3+07h,&BCSCTL1 ; Can RSEL.x be increased?
jz DoneDCO ; 相等返回(jmp> DCO at fastest setting)
inc.b &BCSCTL1 ; BCSCTL1=BCSCTL1+1(Increment RSEL.x)
jmp Test_DCO ; 跳
DoneDCO clr.w &CCTL2 ; Stop CCR2
ret ; Return from subroutine
;
;-----------------------------------------------------------------------------
; Interrupt Vectors Used MSP430x11x1
;-----------------------------------------------------------------------------
ORG 0FFFEh ; MSP430 RESET Vector
DW RESET ;
ORG 0FFF2h ; Timer_A0 Vector
DW TA0_ISR ;
END
