Operations:

Format

Syntax:

Operation:

Operands:

Architecture revision

Opcode

1

mfdr Rd, DebugRegisterNo

Rd = DebugRegister[DebugRegisterAddress << 2];
DebugRegisterNo  ∈ {0, 4, 8, ..., 1020}

Rev1+

111001011011

Rd

00000000

DebugRegisterAddress

12

4

8

8

Description

The instruction copies the value in the specified debug register to the specified register in the register file. Note that special timing concerns must be considered when operating on the debug registers, see the Pipeline Chapter for details.

Status Flags:

Q:

Not affected.

V:

Not affected.

N:

Not affected.

Z:

Not affected.

C:

Not affected.

Note:

Debug registers are implementation defined. If accessing a debug register that does not exist, the result is UNDEFINED.

This instruction can only be executed in a privileged mode. Execution from any other mode will trigger a Privilege Violation exception.