ARM寄存器詳解

1. 31個(gè)通用寄存器

2. 6個(gè)狀態(tài)寄存器

R13作為堆棧指針

R14鏈接寄存器

1.保存函數(shù)返回地址

2. 異常返回地址

R15程序計(jì)數(shù)器（PC指針）

程序狀態(tài)寄存器

只有在異常時(shí)才有程序狀態(tài)寄存器

為什么有兩個(gè)CPSR

SPSR當(dāng)異常發(fā)生時(shí)保存CPSR的地址

當(dāng)異常結(jié)束時(shí)SPSR將之前保存的地址給CPSR

程序狀態(tài)寄存器的數(shù)據(jù)格式

NIs set to bit 31 of the result of the instruction. If this result is regarded as a twos complement
signed integer, then N = 1 if the result is negative and N = 0 if it is positive or zero.

ZIs set to 1 if the result of the instruction is zero (this often indicates anequalresult from a
comparison), and to 0 otherwise.

I bit Disables IRQ interrupts when it is set.

F bitDisables FIQ interrupts when it is set.

M 標(biāo)識處理器的工作模式

獲取和設(shè)置工作模式