Collapse all Symbian^3 Product Developer Library

ARM Exception Types, Fault Status Register Values, and Processor Mode Values

Reference for users of the debug monitor tool to ARM exception types, fault status register values, and processor mode values.

ARM exception types

The numeric value in the left hand column is the value of the ExcId field displayed as a result of entering an f command in the debug monitor.

`00000000`	Prefetch abort
`00000001`	Data abort
`00000002`	Undefined instruction

Fault status register values (FSR register)

The lowest 4-bits of the FSR register indicates the fault generated by the MMU. The FSR register value is displayed as a result of entering an f command in the debug monitor.

`0`	Vector exception
`1`	Alignment fault
`2`	Terminal exception
`3`	Alignment fault
`4`	External abort on linefetch for section translation
`5`	Section translation fault (unmapped virtual address)
`6`	External abort on linefetch for page translation
`7`	Page translation fault (unmapped virtual address)
`8`	External abort on non-linefetch for section translation
`9`	Domain fault on section translation (i.e. accessing invalid domain)
`A`	External abort on non-linefetch for page translation
`B`	Domain fault on page translation (i.e. accessing invalid domain)
`C`	External abort on first level translation
`D`	Permission fault on section (i.e. no permission to access virtual address)
`E`	External abort on second level translation
`F`	Permission fault on page (i.e. no permission to access virtual address)

ARM processor modes (CPSR register)

The 5 least-significant bits of the CPSR register indicate the ARM processor mode. The CPSR register value is displayed as a result of entering an f command in the debug monitor.

CPSR[4:0]	Mode	Register set
10000	User	PC, R14..R0, CPSR
10001	FIQ	PC, R14_fiq..R8_fiq, R7-R0, CPSR, SPSR_fiq
10010	IRQ	PC, R14_irq, R13_irq, R12-R0, CPSR, SPSR_irq
10011	SVC	PC, R14_svc, R13_svc, R12-R0, CPSR, SPSR_sv
10111	Abort	PC, R14_abt, R13_abt, R12-R0, CPSR, SPSR_abt
11011	Undef	PC, R14_und, R13_und, R12-R0, CPSR, SPSR_und
11111	System	PC, R14..R0, CPSR

Parent topic: Debug Monitor Tool