APSR

APSR: Application Program Status Register §

https://developer.arm.com/documentation/ddi0595/2021-12/AArch32-Registers/APSR—Application-Program-Status-Register

Purpose §

• Holds Program status
• Holds Control Information

Configuration §

• Only present when AArch32 is supported.

Attributes §

• 32bit register

Accessing APSR §

• Read
  • MRS
• Write
  • MRS MSR (register)
  • MRS MSR (immediate)

Field Descriptions §

31	30	29	28	27	26~23	22	21~20	19~16	15~10	9	8	7	6	5	4~0
N	Z	C	V	Q	RES0	PAN	RES0	GE	RES0	E	A	I	F	RES0	M

N bit[31] §

• Negative Condition Flag

Z bit[30] §

• Zero Condition Flag
• Field
  • 1: the result of the last flag-setting inst. was zero
  • 0: otherwise

C bit[29] §

• Carry Condition Flag
• Field
  • 1: the last flag-setting instruction resulted in a carry condition
  • 0: otherwise

V bit[28] §

• Overflow Condition Flag
• Field
  • 1: the last flag-setting instruction resulted in an overflow condition
  • 0: otherwise

Q bit[27] §

• Cumulative Saturation Bit
• Field
  • 1: indicates overflow or saturation occurred in some instructions.
  • 0: otherwise

PAN bit[22] §

• Privileged Access Never

GE bit[15:10] §

• Greater than or Equal flags
• For Parallel addition and subtraction

E bit[9] §

• Endianess

A bit[8] §

SError(SystemError) Exception mask bit

A	Meaning
0	Exception not masked
1	Exception masked

I bit[7] §

IRQ mask bit

I	Meaning
0	Exception not masked
1	Exception masked

F bit[6] §

FIQ mask bit

F	Meaning
0	Exception not masked
1	Exception masked