dcps1

Debug Change PE State to EL1

DCPS1 {#<imm>}

Switch to Exception Level 1 (Debug).

Details

Debug instruction that changes the PE to Exception Level 1. This is a privileged instruction typically used in debug state to transition exception levels. The optional immediate provides a 16-bit debug context identifier. Requires debug permissions and is AArch64-only.

Pseudocode Operation

SPSR_EL1 ← PSTATE
PSTATE.EL ← '01'
PC ← DLR_EL0

Example

DCPS1

Encoding

Binary Layout
11010100
101
imm16
000
01
 
Format Exception
Opcode 0xD4A00001
Extension System

Operands

  • imm
    ID

Reference (Arm A64 ISA)

Instruction Forms

Encoding Instruction ISA Bit pattern
0xD4A00001 DCPS1 {#<imm>} A64 11010100 | 101 | imm16 | 000 | 01

Description

Debug Change PE State to EL1, when executed in Debug state: The target exception level of a DCPS1 instruction is: When the target Exception level of a DCPS1 instruction is ELx, on executing this instruction: This instruction is UNDEFINED at EL0 in Non-secure state if EL2 is implemented and HCR_EL2.TGE == 1. This instruction is always UNDEFINED in Non-debug state. For more information on the operation of the DCPS<n> instructions, see DCPS.

Operation

if !Halted() then UNDEFINED;
DCPSInstruction(LL);