修改以上代码，利用汇编语言编程，采集ADC的数字量， 当数字量在0~800之间，LED7（GPIOE13，0xc001e020,配置功能寄存器GPIOEALTFN0，输出使能GPIOEOUTENB，0xc001e004,输出0xc001e000）亮； 当数字量在800~1600之间，LED8（GPIOC17，0xc001c024,配置功能寄存器GPIOCALTFN1，GPIOCOUTENB，0xc001c004,输出0xc001c000）亮； 当数字量在1600~2400之间，LED9（GPIOC8，0xc001c020,寄存器GPIOCALTFN0，输出使能GPIOCOUTENB，0xc001c004,输出0xc001c000）亮； 当数字量在2400~3200之间；LED10（GPIOC7，0xc001c020,配置功能寄存器GPIOCALTFN0，输出使能GPIOCOUTENB，0xc001c004,,输出0xc001c000）亮； 当数字量在3200~4000之间，LED7~LED10全亮，同时蜂鸣器(GPIOC14)响。

以下是修改后的代码，实现了采集ADC的数字量，并根据数字量点亮不同的LED灯以及蜂鸣器。

.arm
.global adc

adc:
    bl led__beep_init      @ 初始化LED和蜂鸣器
    ldr r1, =0xc0012004    @ r1 = 0xc0012004
    ldr r0, [r1]           @ r0 = *r1
    mov r2, #1
    orr r0, r0, r2, lsl #28 @ r0 = r0 | (r2<<28)
    str r0, [r1]           @ *r1 = r0
    
    ldr r1, =0xc0053000    @ r1 = 0xc0053000
    ldr r0, [r1]           @ r0 = *r1
    
    ldr r2, =0xc001e020    @ r2 = 0xc001e020
    ldr r3, =0xc001e004    @ r3 = 0xc001e004
    ldr r4, =0xc001e000    @ r4 = 0xc001e000
    ldr r5, =0xc001c024    @ r5 = 0xc001c024
    ldr r6, =0xc001c004    @ r6 = 0xc001c004
    ldr r7, =0xc001c000    @ r7 = 0xc001c000
    ldr r8, =0xc001c020    @ r8 = 0xc001c020
    ldr r9, =0xc001c008    @ r9 = 0xc001c008
    ldr r10, =0xc001c014   @ r10 = 0xc001c014
    
loop:
    ldr r0, [r1]           @ r0 = *r1
    and r0, r0, #0xFFF     @ r0 = r0 & 0xFFF
    cmp r0, #800
    blt led7               @ 小于800，LED7亮
    cmp r0, #1600
    blt led8               @ 小于1600，LED8亮
    cmp r0, #2400
    blt led9               @ 小于2400，LED9亮
    cmp r0, #3200
    blt led10              @ 小于3200，LED10亮
    b allleds              @ 其他情况，LED7~LED10全亮，蜂鸣器响
    
led7:
    str r4, [r2]           @ LED7亮
    str r2, [r3]           @ GPIOEOUTENB = 1
    str r3, [r5]           @ GPIOEALTFN0 = 0
    b loop
    
led8:
    str r7, [r5]           @ LED8亮
    str r5, [r6]           @ GPIOCOUTENB = 1
    str r6, [r8]           @ GPIOCALTFN1 = 1
    b loop
    
led9:
    str r7, [r8]           @ LED9亮
    str r8, [r6]           @ GPIOCOUTENB = 1
    str r6, [r8]           @ GPIOCALTFN0 = 1
    b loop
    
led10:
    str r7, [r8]           @ LED10亮
    str r8, [r6]           @ GPIOCOUTENB = 1
    str r6, [r9]           @ GPIOCALTFN0 = 1
    str r6, [r10]          @ GPIOCALTFN1 = 1
    b loop
    
alleds:
    str r7, [r2]           @ LED7~LED10全亮
    str r7, [r5]
    str r7, [r8]
    str r2, [r3]           @ GPIOEOUTENB = 1
    str r5, [r6]           @ GPIOCOUTENB = 1
    str r8, [r9]
    str r8, [r10]
    bl led_beep_on         @ 蜂鸣器响
    b loop