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部件号：MSP430FR2355 有关SA如何与ADC输入互连的文档似乎不完整或至少令人困惑！
请参阅6.10 17交叉芯片互联(msp430fr2355.pdf的第83页)，
我们看到SAC0 OA输出(OA0O)在绘图左侧显示一个带有X的正方形。
该处被标记为1.1 ，OA0O，0.1 ，A1
6.11 1端口P1输入/输出(同一文档的第95页)在左上角显示一行(到或从？) ... A1，... OA...，COMP0...和端口P1引脚。
以下第96页建议将“OA0O，0.1 ，A1”的P1SELx设置为11。
在同一页上，它指出，如果要将WFP的1.1 用于I/O，则P1SELx应设置为0 (大概是此处为00？)，同时设置P1DIR以定义输入还是输出。
文件没有表明可以同时将输出内部路由到A1，同时使用WFP 1.1 进行I/O操作！
同样，它也没有指明如果确实可能的话，P1SELx和P1DIR的适当设置是什么(因为我的实验似乎表明是这样)。
我的目标是使用SAC0 (例如，在相关引脚上有一个输入信号，即WFP 1.2 和WFP 1.3)，将输出路由到内部A1，以测量信号。
同时，我想将WFP插脚1.1 用于其他目的，即I/O
(这样就可以获得一个'免费'的额外引脚！ 我的设计缺少针脚...)
(SAC1的输出可以在内部路由到A5，这同样适用于SAC1。)
我已使用以下代码或多或少地回答了我自己的问题。
对于"OA0O，0.1 ，A1"，我将P1SELx设置为11。
我不使用P1DIR做任何事情-因此它的默认值为0，即引脚1.1 在理论上是输入。
尽管如此，我还是能够驱动代码中的针脚H和L来使LED闪烁！
因此，虽然我可能已经用“是的，这似乎是可能的”回答了我的问题，但我有一些担心，我可能会以某种方式滥用MSP430？
可能是使用了WFP 1.1 作为输出(尽管P1DIR为0！) 是否会对其驱动器功能产生影响？
或者是否会对A1产生影响(换用WFP 1.1 时产生的噪音峰值等)？
我还测试了P1DIR，如我的评论所述：
;无论是否使用以下行，功能都是相同的！！！
;BIS.b #BIT1,&P1DIR; WFP 1.1 作为输出(用于驱动外部LED)
我还没有测试过是否可以将WFP 1.1 用作输入。
(假设如果可以，P1DIR将保持其默认设置0？)
[是否与P1OUT和P1IN发生冲突？！！]
总之，请检查我所做的事情是否正常，而不会导致任何潜在的问题...
(对驱动器功能的影响，P1OUT和P1IN之间的冲突，对ADC转换性能的影响...？)
此外，请考虑改进相关文档。
这是我的代码，用于尝试调查正在发生的情况：
SAC0生成一个斜坡信号，该信号在内部路由到A1。
启动板上的绿色和红色LED指示信号测量值分别低于或高于2V。
在主环路中，我会闪存一个由WFP 1.1 驱动的外部LED指示灯，以证明当SAC0驱动ADC的A1时，该引脚可用于输出。
;-------------------------------------------------------------------------------
;
; Attempt to use P1.1 for I/O at same time as SAC OA0O drives A1 ADC
; Starting point was: (my project Asm_SAC_L3_05)
; MSP430FR235x Demo - SAC-L3, DAC Buffer Mode
;
; Description: Configure SAC-L3 for DAC Buffer Mode.
; Use the 12 bit DAC to output positive ramp.
; The OA is set in buffer mode to improve DAC output drive strength.
; Internal 2.5V reference is selected as DAC reference.
; Observe the output of OA0O pin with oscilloscope.
; ACLK = n/a, MCLK = SMCLK = default DCODIV ~1MHz.
;
; Note: period of ramp measures as 504.5 msec (need to check SMCLK freq. and study the timer theory!)
;
; MSP430FR235x
; -------------------
; /|\| |
; | | |
; --|RST DAC12->OA0O|--> oscilloscope
; | |
; | |
; | |
; | |
; | |
;
; Darren Lu, TI
; + own additions ...
;
;-------------------------------------------------------------------------------
.cdecls C,LIST,"msp430.h" ; Include device header file
;-------------------------------------------------------------------------------
.def RESET ; Export program entry-point to
; make it known to linker.
;-------------------------------------------------------------------------------
.text ; Assemble into program memory.
.retain ; Override ELF conditional linking
; and retain current section.
.retainrefs ; And retain any sections that have
; references to current section.
.global ADC_Value ; This is necessary to have ADC_Value recognised in the Expressions window!
.data
.bss ADC_Value, 2
.text
;-------------------------------------------------------------------------------
RESET mov.w #__STACK_END,SP ; Initialiwe stackpointer
StopWDT mov.w #WDTPW|WDTHOLD,&WDTCTL ; Stop watchdog timer
; Disable the GPIO power-on default high-impedance mode
; to activate previously configured port settings
bic.w #LOCKLPM5,&PM5CTL0 ; (Turn off digital I/O)
mov.b #PMMPW_H,&PMMCTL0_H ; Unlock the PMM registers
mov.w #INTREFEN+REFVSEL_2,&PMMCTL2; Enable internal 2.5V reference
PollRef bit.w #REFGENRDY,&PMMCTL2 ; Poll till internal reference settles
jz PollRef ;
; Despite the following settings for P1SEL0 and P1SEL1, I am still also able to use P1.1 as an independent output!
SetPin bis.b #BIT1,&P1SEL0 ; Select P1.1 as OA0O function
bis.b #BIT1,&P1SEL1 ; OA is used as buffer for DAC.
mov.w #DACSREF_1+DACLSEL_2+DACIE,&SAC0DAC; Select (2.5V, defined above) int Vref as DAC ref,
; DAC always loads data from DACDAT at the +ve edge of TB2.1B signal,
; Enable DAC interrupt
;mov.w #0,R13
;clr.w R13
;mov.w R13,&SAC0DAT ; Initial DAC data
clr.w &SAC0DAT ; Initial DAC data=0 (DHBR simplification not involving use of R13)
bis.w #DACEN,&SAC0DAC ; Enable DAC
mov.w #NMUXEN+PMUXEN+PSEL_1+NSEL_1,&SAC0OA; Enable negative (follower) and positive (DAC) input
bis.w #OAPM,&SAC0OA ; Select low speed and low power mode
mov.w #MSEL_1,&SAC0PGA ; Set OA as buffer mode
bis.w #SACEN+OAEN,&SAC0OA ; Enable SAC and OA
; Use TB2.1B as DAC hardware trigger
mov.w #0x63,&TB2CCR0 ; PWM Period/2
mov.w #OUTMOD_6,&TB2CCTL1; ; TBCCR1 toggle/set
mov.w #0x32,&TB2CCR1 ; TBCCR1 PWM duty cycle
mov.w #TBSSEL__SMCLK+MC_1+TBCLR,&TB2CTL ; SMCLK, up mode, clear TB2R
; -- Configure ports for LEDs (based on code from Asm_ADC_Sampling_P1.2_LPM)
;bic.b #BIT0, &P1OUT ; LED1 (red) = 0 (Off)
bis.b #BIT0, &P1DIR ; Configure LED1 (red) as output
;bic.b #BIT6, &P6OUT ; LED2 (green) = 0 (Off)
bis.b #BIT6, &P6DIR ; Configure LED2 (green) as output
; Functionality is the same whether or not following line is used!!!
;bis.b #BIT1, &P1DIR ; P1.1 as output (to drive external LED)
bic.b #LOCKLPM5, &PM5CTL0 ; Turn on digital I/O
; -- setup ADC (based on code from Asm_ADC_Sampling_P1.2_LPM)
bic.w #ADCSHT0, &ADCCTL0 ; Clear bit 0 (bit 8 of register) of default ADCSHT=01
bis.w #ADCSHT1, &ADCCTL0 ; Conversion = 16 ADCCLK cycles (0010b)
;mov.w #ADCSHT_2|ADCON, &ADCCTL0 ; Conversion = 16 ADCCLK cycles (0010b). Hao uses instead of the above two lines.
bis.w #ADCON, &ADCCTL0 ; Turn ADC on
bis.w #ADCSSEL_3, &ADCCTL1 ; ADC clock signal = SMCLK (1MHz). Hao uses the default MODOSC (MODCLK). msp430fr2355 page 68: 3.8MHz +/- 21%
bis.w #ADCSHP_1, &ADCCTL1 ; SAMPCON signal is sourced from the sampling timer
bic.w #ADCRES0, &ADCCTL2 ;
bis.w #ADCRES_2, &ADCCTL2 ; Resolution = 12-bit (ADRED=10)
bis.w #ADCINCH_1, &ADCMCTL0 ; ADC input channel A1 (P1.1) (hoping to be able to use P1.1 also for I/O?!)
bis.w #ADCIE0, &ADCIE ; Enable ADC conversion complete IRQ
bis.w #ADCENC|ADCSC, &ADCCTL0 ; Enable and start ADC conversion
;nop
;bis.w #LPM3+GIE,SR ; Enter LPM3, Enable Interrupt For Lu (and here) code will sit here, with interrupts continuing to be serviced.
;nop
nop
bis.w #GIE,SR ; Enable global interrupts
nop
main:
bis.w #LPM3,SR ; Enter LPM3
bis.w #ADCENC|ADCSC, &ADCCTL0 ; Enable and start ADC conversion
clr.w R4
DelayLoop inc.w R4 ; Based on Davies page 95 (approx 0.7 sec)
cmp.w #50000,R4
jne DelayLoop
xor.b #BIT1, &P1OUT ; toggle LED
jmp main
;-------------------------------------------------------------------------------
; ISR for SAC0 (note that shares same vector as for SAC2)
;-------------------------------------------------------------------------------
SAC0_ISR: add.w &SAC0IV,PC
reti ; Vector 0: No interrupt
reti ; Vector 2: (reserved)
;jmp SACDACMODE ; Vector 4: SAC DAC Interrupt (other vectors are reserved)
;SACDACMODE
;add.w #1,R13 ;
;and.w #0xFFF,R13 ;
;mov.w R13,&SAC0DAT ; DAC12 output positive ramp
inc.w &SAC0DAT ; DAC12 output positive ramp (DHBR simplification not involving use of R13)
bic.w #LPM3, 0(SP) ; Cancel LPM3 on exit. i.e., return to active mode
reti
; Code would be more robust if check ADCIV register.
; There could be other interrupts for overflows, etc.
; Hao code does this. Note that, with his code, other types of interrupt will not result in exit from LPM0. That is okay/ correct!
ADC_ISR:
;mov.w &ADCIV, PC ; Add offset to PC and clear the associated interrupt
; ...
mov.w &ADCMEM0, ADC_Value ; No need for own variable! Could use &ADCMEM0 in following (but would flag be cleared?)! Or R4.
;mov.w &ADCMEM0, R4
cmp.w #2482, ADC_Value
;cmp.w #1000, ADC_Value
;cmp.w #1000, R4
jhs ge2V
bic.b #BIT0, &P1OUT ; For A2 < 2V: LED1 (red) OFF
bis.b #BIT6, &P6OUT ; LED2 (green) ON
jmp ADC_ISR_end
ge2V: bis.b #BIT0, &P1OUT ; For A2 >= 2V: LED1 (red) ON
bic.b #BIT6, &P6OUT ; LED2 (green) OFF
ADC_ISR_end:
;;bic.w #CPUOFF, SR ; For video 15.2(d). Exit LPM0 on return. bic.w #CPUOFF, 0(SR) used by Hao in 12976 code.
; bic.w #CPUOFF, 0(SP) ; As used by Hao in 12976 code. Refer also Davies page 203 to 205.
;bic.w #LPM0, 0(SP) ; (same as #CPMOFF)
reti
;-------------------------------------------------------------------------------
; Stack Pointer definition
;-------------------------------------------------------------------------------
.global __STACK_END
.sect .stack
;-------------------------------------------------------------------------------
; Interrupt Vectors
;-------------------------------------------------------------------------------
.sect ".reset" ; MSP430 RESET Vector
;.sect RESET_VECTOR ; Variant used by Lu
.short RESET
;.sect SAC0_SAC2_VECTOR ; Lu (this is the C definition)
.sect ".int27" ; LaMeres
.short SAC0_ISR
.sect ".int29"
.short ADC_ISR
.end
非常感谢您的帮助！
