AMCNTENCLR

Disable control bits for the architected and auxiliary activity monitors event counters, AMU.AMEVCNTR0<n>. and AMU.AMEVCNTR1<n>.

Configuration

External register AMCNTENCLR bits [31:0] are architecturally mapped to AArch64 System register AMCNTENCLR0_EL0[31:0].

External register AMCNTENCLR bits [63:32] are architecturally mapped to AArch64 System register AMCNTENCLR1_EL0[31:0].

It is IMPLEMENTATION DEFINED whether AMCNTENCLR is implemented in the Core power domain or in the Debug power domain.

This register is present only when FEAT_AMUv1 is implemented and FEAT_AMU_EXT64 is implemented. Otherwise, direct accesses to AMCNTENCLR are RES0.

Attributes

Field descriptions

Bits [63:48]

P1<n>, bit [n+32], for n = 15 to 0

Activity monitor event counter disable bit for AMEVCNTR1<n>.

When N is less than 16, bits [15:N] are RAZ, where N is the value in AMCGCR.CG1NC.

Possible values of each bit are:

P1<n>	Meaning
0b0	When read, means that AMEVCNTR1<n> is disabled.
0b1	When read, means that AMEVCNTR1<n> is enabled.

The reset behavior of this field is:

On an AMU reset, this field resets to 0.

Bits [31:16]

Bits [15:4]

Reserved, RAZ/WI.

This field is reserved for additional architected activity monitor event counters, which Arm might define in a future version of the Activity Monitors architecture.

P0<n>, bit [n], for n = 3 to 0

Activity monitor event counter disable bit for AMEVCNTR0<n>.

Note

AMCGCR.CG0NC identifies the number of architected activity monitor event counters. In an implementation that includes FEAT_AMUv1, the number of architected activity monitor event counters is 4.

Possible values of each bit are:

P0<n>	Meaning
0b0	When read, means that AMEVCNTR0<n> is disabled.
0b1	When read, means that AMEVCNTR0<n> is enabled.

The reset behavior of this field is:

On an AMU reset, this field resets to 0.

Accessing AMCNTENCLR

If the number of auxiliary activity monitor event counters implemented is zero, reads of AMCNTENCLR[63:32] are RAZ. Software must treat reserved accesses as RES0. See 'Access requirements for reserved and unallocated registers'.

Note

The number of auxiliary activity monitor event counters implemented is zero exactly when AMU.AMCFGR.NCG == 0b0000.

Accesses to this register use the following encodings:

Accessible at offset 0xC20 from AMU

Accesses on this interface are RO.

63	62	61	60	59	58	57	56	55	54	53	52	51	50	49	48	47	46	45	44	43	42	41	40	39	38	37	36	35	34	33	32
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
RES0																P115	P114	P113	P112	P111	P110	P19	P18	P17	P16	P15	P14	P13	P12	P11	P10
RES0																RAZ/WI												P03	P02	P01	P00

AMCNTENCLR, Activity Monitors Count Enable Clear Register

Purpose