ARM ARM7TDMI User Manual download pdf (Page 27)

Page 23

4.19 MRS – Move PSR into General-Purpose Register

Syntax:

MRS{<cond>} <Rd >, CPSR

MRS{<cond>} <Rd >, SPSR

RTL:

if(cond)

Rd  CPSR/SPSR

Flags updated:

None

Encoding:

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

cond 0 0 0 1 0 R 0 0 SB0 Rd SB0

Usage and Examples:

Moves the value of CPSR or the current SPSR into a general-purpose register.

MRS R0, CPSR

4.20 MSR – Move to Status Register from ARM Register

Syntax:

MSR{<cond>} CPSR_<fields>, #<immediate>

MSR{<cond>} CPSR_<fields>, <Rm>

MSR{<cond>} SPSR_<fields>, #<immediate>

MSR{<cond>} SPSR_<fields>, <Rm>

RTL:

if(cond)

CPSR/SPSR  immediate/register value

Flags updated:

N/A

Encoding:

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

cond 0 0 1 1 0 R 1 0 field_mask SB0 rotate_imm immediate

cond 0 0 0 1 0 R 1 0 field_mask SB0 SBZ 0 0 0 0 Rm

Usage and Examples:

Moves the value of a register or immediate operand into the CPSR or the current SPSR.

This instruction is typically used by supervisory mode code. Further details on this

instruction can be found in the ARM Architecture Reference Manual.

1 2 ... 22 23 24 25 26 27 28 29 30 31 32 ... 42 43

No comments

ARM ARM7TDMI User Manual Page 27