我目前正在编写一些基本的ARM汇编程序。我们的想法是控制LPC2378开发板上的理论炉和冷却/加热系统，并附带一个应用板。
就识别来自设备的输入而言，我到了那里。但是，我无法正确使用我的循环，我希望你们可以指出为什么我的循环卡住了，即使按下按钮1后，风扇也没有打开。我以前让风扇工作，但是当我开始尝试通过加热器的温度控制风扇时，它似乎没有启动，加热器保持开启，变得更热和更热，没有风扇冷却它。
我猜它可能归结为我从ADC控制器读取温度的方式。
请不要犹豫，询问您是否需要更多信息来回答这个问题。
;=========================================================================
; MotorControl_1
;
; BUT1 turns motor ON and BUT2 turns motor OFF
;
; No interrupt support (except for Reset) - as simple as it gets!
;
; WDH, November 2008
;==========================================================================
; Set-up interrupt vectors and stack support
$ LPC2378InterruptVectors.s
; After a reset exception, execution starts here - the processor is in ARM
; mode and supervisor state with interrupts disabled
SECTION .text:CODE:NOROOT(2)
REQUIRE __vector ; Forces reference to this symbol - required by linker
ARM
; __iar_program_start - defined start symbol.
__iar_program_start:
; Include lpc2378 IO register definitions
#include "iolpc2378.h"
; Include Olimex LPC-2378-STK IO definitions
#include "OlimexLPC2378BoardDefs.h"
; Main entry point - required by debugger
;=========================================================================
; main starts here
;=========================================================================
main
;=========================================================================
; Stack setup
;
; Stack pointer (r13 or SP) is assigned the highest address in a 32kB
; section of on-chip SRAM - assumes a FULL descending stack convention
;=========================================================================
ldr r13, = 0x40008000
ldr r2, = 0x000050 ;Load the delay value
ldr r3, = 0x028 ;Start set point at 40
ldr r4, = 0x000 ;Start temp difference as 0
; ldr r6, = 0x0f ;Temp High Value (15)
; ldr r7, = -0xF ;Set r7 to -15.
; Initialise IO
BL InitialiseARM_IO
BL InitialiseApplicationsBoard_IO
; Initialise the devices and display
BL FanOff
BL errorLedOff
BL systemLedOff
BL heaterOff
LoopStart
BL WaitBUT1
BL heaterOn
BL systemLedOn
BL readTemp
BL checkTemp
CMP r0, #5
BGT errorVal
SUBS r7, r6, r4 ;Performs r7 = r6 - r4 and sets condition register
BLT LoopStart ;Branches to label_bar if r7 < 0 (in which case r6 < r4)
BGT heaterOff
BGT errorLedOn
BGT FanOn
BGT LoopStart
BL WaitBUT2
BL FanOff
BL errorLedOff
BL systemLedOff
BL heaterOff
B LoopStart
;=========================================================================
; InitialiseARM_IO
;
; Initialise the ARM interface, as follows:
;
; Port0(13..14} GPIO Output to on-board LEDs
; bit 13: USB_LINK LED
; bit 14: USB_CONNECT LED
; Port0{18,29} GPIO Input from BUT1 and BUT2
; bit 18: BUT2 pressbutton input
; bit 29: BUT1 pressbutton input
; Port1{18,19} GPIO Inputs from joystick UP and DOWN
; bit 18: UP joystick inout
; bit 19: DOWN joystick input
;=========================================================================
InitialiseARM_IO
; Define data direction for LEDs - the LEDs are connected
; to P0.13 and P0.14
STMFD r13!,{r0,r5,r14} ; Push r0, r5 and LR
;LEDs on ARM board:
; Assign GPIO on P0.13 and P0.14
LDR R5, =PINSEL0 ; Address of PINSEL0
LDR R0, [R5] ; Read current PINSEL0
BIC R0, R0, #0x3C000000 ; Clear bits 26..29
STR R0, [R5] ; Put back in PINSEL0
; Configure output for P0.13 and P0.14
LDR R5, =IO0DIR ; Address of IO0DIR
LDR R0, [R5] ; Read current IO0DIR
ORR R0, R0, #0x6000 ; Set bits 13 and 14 - for P0.13 and P0.14
STR R0, [R5] ; Put back in IO0DIR
; Switches and Joystick inputs on ARM board
; Assign GPIO on P0.18 and P0.29
LDR R5, =PINSEL1 ; Address of PINSEL1
LDR R0, [R5] ; Read current PINSEL1
BIC R0, R0, #0x30 ; Clear bits 4..5
BIC R0, R0, #0x0c000000 ; Clear bits 26..27
STR R0, [R5] ; Put back in PINSEL0
; Configure input for P0.18 and P0.29
LDR R5, =IO0DIR ; Address of IO0DIR
LDR R0, [R5] ; Read current IO0DIR
BIC R0, R0, #0x20000000 ; Clear bits 18 and 29 - for P0.18 and P0.29
BIC R0, R0, #0x00040000
STR R0, [R5] ; Put back in IO0DIR
; Assign GPIO on P1.18 and P1.19
LDR R5, =PINSEL3 ; Address of PINSEL3
LDR R0, [R5] ; Read current PINSEL3
BIC R0, R0, #0xF0 ; Clear bits 4..7
STR R0, [R5] ; Put back in PINSEL3
; Configure input for P1.18 and P1.19
LDR R5, =IO1DIR ; Address of IO1DIR
LDR R0, [R5] ; Read current IO1DIR
BIC R0, R0, #0xc0000 ; Clear bits 18 and 19 - for P1.18 and P1.19
STR R0, [R5] ; Put back in IO1DIR
LDMFD r13!,{r0,r5,r14} ; Pop r0, r5 and LR
mov pc, r14 ; Put link register back into PC
;=========================================================================
; InitialiseApplicationsBoard_IO
;
; Initialise the interface to the Applications Board, as follows:
;
; Port4{0..7} GPIO Output to LEDs, Motor and Heater
; bits 0..4: Temperature error LED indicators
; bit 5: Heater control
; bits 6..7: Motor control
; Port4(8..15} GPIO Input from ADC
; bits 8..15: Inputs from Application Board ADC
;
;=========================================================================
InitialiseApplicationsBoard_IO
; Define data direction for LEDs - the LEDs are connected
; to P0.13 and P0.14
STMFD r13!,{r0,r5,r14} ; Push r0, r5 and LR
; Applications Board Interface via Port4
; Set FIO4MASK to allow access to all bits
LDR R5, =FIO4MASK ; Address of FIO4DIR
LDR R0, [R5] ; Read current IO4DIR
MOV R0, #0x0 ; Clear all bits of FIO4MASK
STR R0, [R5] ; Put back in IO4DIR
; Configure output for P4.0 to P4.7
LDR R5, =FIO4DIR ; Address of FIO4DIR
LDR R0, [R5] ; Read current IO4DIR
ORR R0, R0, #0xFF ; Set bits 0..7 - for P4.0 and P4.7
STR R0, [R5] ; Put back in IO4DIR
; Configure input for P4.8 to P4.15
LDR R5, =FIO4DIR ; Address of FIO4DIR
LDR R0, [R5] ; Read current IO4DIR
BIC R0, R0, #0xFF00 ; Clear bits 8..15 - for P4.8 and P4.15
STR R0, [R5] ; Put back in IO4DIR
LDMFD r13!,{r0,r5,r14} ; Pop r0, r5 and LR
mov pc, r14 ; Put link register back into PC
;=========================================================================
; Wait for BUT1 to be pressed
;=========================================================================
WaitBUT1
STMFD r13!,{r0,r5,r14} ; Push r0, r5 and LR
WaitForBUT1Pressed
ldr r0, = IO0PIN ; Address of FIO0PIN register
ldr r1, [r0] ; Read FIO0PIN in to r1
ands r1, r1, # B1_MASK ; Mask out BUT1
beq BUT1Pressed ; Exit LED toggle loop if button is pressed
B WaitForBUT1Pressed
BUT1Pressed
LDMFD r13!,{r0,r5,r14} ; Pop r0, r5 and LR
mov pc, r14 ; Put link register back into PC
;=========================================================================
; Wait for BUT2 to be pressed
;=========================================================================
WaitBUT2
STMFD r13!,{r0,r5,r14} ; Push r0, r5 and LR
WaitForBUT2Pressed
ldr r0, = IO0PIN ; Address of FIO0PIN register
ldr r1, [r0] ; Read FIO0PIN in to r1
ands r1, r1, # B2_MASK ; Mask out BUT1
beq BUT2Pressed ; Exit LED toggle loop if button is pressed
B WaitForBUT2Pressed
BUT2Pressed
LDMFD r13!,{r0,r5,r14} ; Pop r0, r5 and LR
mov pc, r14 ; Put link register back into PC
;=========================================================================
; Turn Fan Motor ON
;=========================================================================
FanOn
STMFD r13!,{r0,r5,r14} ; Push r0, r5 and LR
LDR R5, =FIO4PIN ; Address of FIO4PIN
LDR r0, [r5] ; Read current Port4
ORR r0, r0, #0x80
STR r0, [r5] ; Output
LDMFD r13!,{r0,r5,r14} ; Pop r0, r5 and LR
mov pc, r14 ; Put link register back into PC
;=========================================================================
; Turn Fan Motor OFF
;=========================================================================
FanOff
STMFD r13!,{r0,r5,r14} ; Push r0, r5 and LR
LDR R5, =FIO4PIN ; Address of FIO4PIN
LDR r0, [r5] ; Read current Port4
BIC r0, r0, #0xc0
STR r0, [r5] ; Output
LDMFD r13!,{r0,r5,r14} ; Pop r0, r5 and LR
mov pc, r14 ; Put link register back into PC
;==============================================================================
; Turn On Error LED
;==============================================================================
errorLedOn
STMFD r13!,{r0, r5,r14}
mov r0, # USB_LINK_LED_MASK
ldr r5, = IO0CLR
str r0, [r5]
LDMFD r13!,{r0, r5, r14}
mov pc, r14
;==============================================================================
; Turn Off Error LED
;==============================================================================
errorLedOff
STMFD r13!,{r0, r5,r14}
mov r0, # USB_LINK_LED_MASK
ldr r5, = IO0SET
str r0, [r5]
LDMFD r13!,{r0, r5, r14}
mov pc, r14
;==============================================================================
; Turn On System LED
;==============================================================================
systemLedOn
STMFD r13!,{r0, r5,r14}
mov r0, # USB_CONNECT_LED_MASK
ldr r5, = IO0CLR
str r0, [r5]
LDMFD r13!,{r0, r5, r14}
mov pc, r14
;==============================================================================
; Turn Off System LED
;==============================================================================
systemLedOff
STMFD r13!,{r0, r5,r14}
mov r0, # USB_CONNECT_LED_MASK
ldr r5, = IO0SET
str r0, [r5]
LDMFD r13!,{r0, r5, r14}
mov pc, r14
;==============================================================================
; Turn Heater On
;==============================================================================
heaterOn
STMFD r13!,{r0,r5,r14} ; Push r0, r5 and LR
LDR R5, =FIO4PIN ; Address of FIO4PIN
LDR r0, [r5] ; Read current Port4
ORR r0, r0, #0x20
STR r0, [r5] ; Output
LDMFD r13!,{r0,r5,r14} ; Pop r0, r5 and LR
mov pc, r14 ; Put link register back into PC
;==============================================================================
; Turn The Heater Off
;==============================================================================
heaterOff
STMFD r13!,{r0,r5,r14} ; Push r0, r5 and LR
LDR R5, =FIO4PIN ; Address of FIO4PIN
LDR r0, [r5] ; Read current Port4
AND r0, r0, #0xDF
STR r0, [r5] ; Output
LDMFD r13!,{r0,r5,r14} ; Pop r0, r5 and LR
mov pc, r14 ; Put link register back into PC
;==============================================================================
; Read Temperature
;==============================================================================
readTemp
STMFD r13!,{r0,r5,r14} ; Push r0, r5 and LR
LDR r0, =FIO4PIN
LDR r1, [r0]
LSR r1, r1, #8
AND r1, r1, #0xFF ; r1 now holds the temperature value
LDMFD r13!,{r0,r5,r14} ; Pop r0, r5 and LR
mov pc, r14 ; Put link register back into PC
;==============================================================================
; Implement Counter And Read Temperature
;==============================================================================
checkTemp
STMFD r13!,{r0, r14} ; Push PC, r0, Lr
LSR r1, r1, #8
LDR r0, [r2] ; Load delay value in r0.
SUB r0, r0, #0x01 ; Minus 1 from delay.
BEQ readTemp ; Branch if timer counted down.
errorVal
STMFD r13!,{r0, r14} ; Push PC, r0, Lr
SUB r1, r3, r6 ; Subtract set point from temperature, into r6
mov pc, r14 ; Put link register back into PC
END
答案 0 :(得分：7)
看起来你已经把BGT（如果大于）的分支与BLGT（分支和链接，如果大于）混淆了。在主循环的中间你有这个：
BLT LoopStart ;Branches to label_bar if r7 < 0 (in which case r6 < r4)
BGT heaterOff
BGT errorLedOn
BGT FanOn
BGT LoopStart
如果条件是“大于”，则代码将转移到 heaterOff ，然后当该函数返回时，它将完全退出代码。函数 errorLedOn 和 FanOn 永远无法执行。