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INSTRUCTION SET
S3C2501X
3-22
3.6.4 ASSEMBLER SYNTAX
— MRS - transfer PSR contents to a register
MRS{cond} Rd,<psr>
— MSR - transfer register contents to PSR
MSR{cond} <psr>,Rm
— MSR - transfer register contents to PSR flag bits only
MSR{cond} <psrf>,Rm
The most significant four bits of the register contents are written to the N,Z,C & V flags respectively.
— MSR - transfer immediate value to PSR flag bits only
MSR{cond} <psrf>, <#expression>
The expression should symbolise a 32 bit value of which the most significant four bits are written to the N, Z, C
and V flags respectively.
Key:
{cond}
Two-character condition mnemonic. See Table 3-2.
Rd and Rm
Expressions evaluating to a register number other than R15
<psr>
CPSR, CPSR_all, SPSR or SPSR_all. (CPSR and CPSR_all are synonyms as are
SPSR
and SPSR_all)
<psrf>
CPSR_flg or SPSR_flg
<#expression>
Where this is used, the assembler will attempt to generate a shifted immediate 8-bit
field to match the expression. If this is impossible, it will give an error.
Examples
In User mode the instructions behave as follows:
MSR
CPSR_all,Rm
; CPSR[31:28]
←
Rm[31:28]
MSR
CPSR_flg,Rm
; CPSR[31:28]
←
Rm[31:28]
MSR
CPSR_flg,#0xA0000000
; CPSR[31:28]
←
0xA (set N, C; clear Z, V)
MRS
Rd,CPSR
; Rd[31:0]
←
CPSR[31:0]
In privileged modes the instructions behave as follows:
MSR
CPSR_all,Rm
; CPSR[31:0]
←
Rm[31:0]
MSR
CPSR_flg,Rm
; CPSR[31:28]
←
Rm[31:28]
MSR
CPSR_flg,#0x50000000
; CPSR[31:28]
←
0x5 (set Z, V; clear N, C)
MSR
SPSR_all,Rm
; SPSR_<mode>[31:0]
←
Rm[31:0]
MSR
SPSR_flg,Rm
; SPSR_<mode>[31:28]
←
Rm[31:28]
MSR
SPSR_flg,#0xC0000000
; SPSR_<mode>[31:28]
←
0xC (set N, Z; clear C, V)
MRS
Rd,SPSR
; Rd[31:0]
←
SPSR_<mode>[31:0]
Summary of Contents for S3C2501X
Page 18: ......
Page 275: ...MEMORY CONTROLLER S3C2501X 5 60 NOTES ...
Page 289: ...I2C CONTROLLER S3C2501X 6 14 NOTES ...
Page 373: ...GDMA CONTROLLER S3C2501X 9 24 NOTES ...
Page 435: ...I O PORTS S3C2501X 12 12 NOTES ...