ISB

Instruction synchronization barrier

This instruction flushes the pipeline in the PE and is a context synchronization event. For more information, see Instruction Synchronization Barrier (ISB).

Encoding: System

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
1	1	0	1	0	1	0	1	0	0	0	0	0	0	1	1	0	0	1	1					1	1	0	1	1	1	1	1
																				CRm					opc		Rt

ISB {<option>|#<imm>}

Decoding algorithm

// No additional decoding required

Operation

InstructionSynchronizationBarrier();

if IsFeatureImplemented(FEAT_BRBE) && BRBEBranchOnISB() then
    BRBEISB();

Explanations

<option>: Specifies an optional limitation on the barrier operation. Values are:
All other encodings of "CRm" are reserved. The corresponding instructions execute as full system barrier operations, but must not be relied upon by software.
<imm>: Is an optional 4-bit unsigned immediate, in the range 0 to 15, defaulting to 15 and encoded in the "CRm" field.