dcread

Data Cache Read

dcread RT, RA, RB

Reads a data cache tag or data (Debug).

Details

Reads and returns a data cache tag or data value from the address RA + RB into register RT. This is an embedded debug/diagnostic instruction used to inspect data cache contents; exact behavior (tag vs. data read, selection mechanism) is implementation-dependent. The instruction requires supervisor privilege and may not be available on all embedded PowerPC implementations.

Pseudocode Operation

addr ← (RA) + (RB)
RT ← Read data cache entry at addr

Example

dcread r3, r4, r5

Encoding

Binary Layout
31
0
RT
6
RA
11
RB
16
486
21
/
31
 
Format X-form
Opcode 0x7C0003CC
Extension Embedded

Operands

  • RT
    Target
  • RA
    Base
  • RB
    Index