pdf-to-md-test/page_237_cfsr.md

4.4.10 Configurable fault status register (CFSR; UFSR+BFSR+MMFSR)

Address offset: 0x28 Reset value: 0x0000 0000 Required privilege: Privileged

The CFSR is byte-accessible and indicates the cause of a memory management fault, bus fault, or usage fault.

CFSR subregisters

Subregister	Address	Access
MMFSR	Bits[7:0]	Byte access at 0xE000ED28
BFSR	Bits[15:8]	Byte access at 0xE000ED29
UFSR	Bits[31:16]	Halfword access at 0xE000ED2A
Full CFSR	Bits[31:0]	Word access at 0xE000ED28

Bitfield definitions

UFSR — Usage Fault Status Register (Bits[31:16])

Bit	Field	Type	Description
31	DIVBY	rc_w1	Divide by zero trap
30	ZERO	rc_w1	Unaligned memory access trap
29	UNALI	rc_w1	Unaligned access fault
28	UNALIGNED	rc_w1	Unaligned memory access fault
27	Reserved	-	-
26	NOCP	rc_w1	No coprocessor fault
25	INVPC	rc_w1	Invalid PC load fault
24	INVSTATE	rc_w1	Invalid state fault
23	UNDEF	rc_w1	Undefined instruction fault
22	Reserved	-	-
21	INSTR	rc_w1	Instruction access fault

BFSR — Bus Fault Status Register (Bits[15:8])

Bit	Field	Type	Description
15	BFARVALID	rc_w1	Bus Fault Address Register valid
14	Reserved	-	-
13	LSPERR	rw	Lazy save error
12	STKERR	rw	Stack error
11	UNSTKERR	rw	Unstack error
10	IMPRECISERR	rw	Imprecise data access error
9	PRECISERR	rw	Precise data access error
8	IBUSERR	rw	Instruction bus error

MMFSR — Memory Management Fault Status Register (Bits[7:0])

Bit	Field	Type	Description
7	MMARVALID	rc_w1	Memory Management Fault Address Register valid
6	Reserved	-	-
5	MLSPERR	rw	Lazy save error (memory management)
4	MSTKERR	rw	Stack error (memory management)
3	MUNSTKERR	rw	Unstack error (memory management)
2	Reserved	-	-
1	DACCVIOL	rw	Data access violation
0	IACCVIOL	rw	Instruction access violation

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See also

• Usage fault status register (UFSR) — page 238
• Bus fault status register (BFSR) — page 239
• Memory management fault address register (MMFSR) — page 240