Arm Register

ARM has 31 general-purpose 32-bit registers. At any one time, 16 of these registers are visible. The other
registers are used to speed up exception processing. All the register specifiers in ARM instructions can
address any of the 16 visible registers.

 

 

有31个寄存器？ 可能不同版本的arm不一样吧。 不过有16个寄存器可见，r0-r15? 没算上status register? 可能是单独算的。

 

其中r13是Stack Pointer (sp)， r14是Link Register (lr)， r15是Program Counter (pc)。 其余的可以随意使用。

 

 

All processor state other than the general-purpose register contents is held in status registers. The current
operating processor status is in the Current Program Status Register (CPSR)

 

这里说的就是Status Register 状态寄存器了。 和x86类似，保存了一些指令的执行的状态。

 

Each exception mode also has a Saved Program Status Register (SPSR) which holds the CPSR of the task
immediately before the exception occurred. The CPSR and the SPSRs are accessed with special
instructions.

 

而每个exception mode中又有一个spsr。