GMID_EL1

Indicates the block size that is accessed by the LDGM and STGM System instructions.

Configuration

This register is present only when FEAT_MTE2 is implemented. Otherwise, direct accesses to GMID_EL1 are UNDEFINED.

Attributes

Field descriptions

Bits [63:4]

BS, bits [3:0]

Log₂ of the block size in words. The minimum supported size is 16B (value == 2) and the maximum is 256B (value == 6).

This field has an IMPLEMENTATION DEFINED value.

Access to this field is RO.

Accessing GMID_EL1

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, GMID_EL1

op0	op1	CRn	CRm	op2
0b11	0b001	0b0000	0b0000	0b100

if PSTATE.EL == EL0 then if IsFeatureImplemented(FEAT_IDST) then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); else UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && HCR_EL2.TID5 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else X[t, 64] = GMID_EL1; elsif PSTATE.EL == EL2 then X[t, 64] = GMID_EL1; elsif PSTATE.EL == EL3 then X[t, 64] = GMID_EL1;

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
RES0																												BS

GMID_EL1, Multiple tag transfer ID Register