LDR{條件} 目的寄存器 <存儲器地址>

LDR R0，[R1] ；將存儲器地址為R1的字?jǐn)?shù)據(jù)讀入寄存器R0。LDR R0，[R1，R2] ；將存儲器地址為R1+R2的字?jǐn)?shù)據(jù)讀入寄存器R0。LDR R0，[R1，#8] ；將存儲器地址為R1+8的字?jǐn)?shù)據(jù)讀入寄存器R0。LDR R0，[R1],R2 ；將存儲器地址為R1的字?jǐn)?shù)據(jù)讀入寄存器R0，并將R1+R2的值存入R1。LDR R0，[R1],#8 ；將存儲器地址為R1的字?jǐn)?shù)據(jù)讀入寄存器R0，并將R1+8的值存入R1。LDR R0，[R1，R2]! ；將存儲器地址為R1+R2的字?jǐn)?shù)據(jù)讀入寄存器R0，并將R1+R2的值存入R1。LDR R0，[R1，LSL #3] ；將存儲器地址為R1*8的字?jǐn)?shù)據(jù)讀入寄存器R0。LDR R0，[R1，R2，LSL #2] ；將存儲器地址為R1+R2*4的字?jǐn)?shù)據(jù)讀入寄存器R0。LDR R0，[R1,,R2，LSL #2]??；將存儲器地址為R1+R2*4的字?jǐn)?shù)據(jù)讀入寄存器R0，并將R1+R2*4的值存入R1。LDR R0，[R1],R2，LSL #2 ；將存儲器地址為R1的字?jǐn)?shù)據(jù)讀入寄存器R0，并將R1+R2*4的值存入R1。LDR R0，Label ；Label為程序標(biāo)號，Label必須是當(dāng)前指令的-4~4KB范圍內(nèi)。

LDR Rd，[Rn]，#0x04 ；這里Rd不允許是R15。

LDR R0，=0xff

//main.c#include 
int main(void){ RCC->APB2ENR |= RCC_APB2ENR_IOPBEN;
 GPIOB->CRL &= ~(0xf<<(1*4));
 GPIOB->CRL |= 0x2<<(1*4); 
 GPIOB->ODR &= ~(1<<1);
 return 0; }
//main.h#define RCC_APB2ENR (*(unsigned int *)0x40021018)#define GPIOB_CRL (*(unsigned int *)0x40010c00)#define GPIOB_ODR (*(unsigned int *)0x40010c0c)

LDR r0,[r1] r0 = *r1
STR r0,[r1] *r1 = r0
MOV?r0，r1????r1->r0拷貝?

r0 = * 0x0800 017c

　　* 0x0800 017c=0x4002 1000

*0x4001 0c00 &= ~(0xf0) r1 = *0x4001 0c00 *0x4001 0c00 &= ~(0xf0)

***0x4001 0c00 |= 0x20 0x4001 0c0c &= ~(0x02)*