eciwx

External Control In Word Indexed

eciwx RT, RA, RB

Loads a word from an external device using the EAR register.

Encoding

Binary Layout

31

0:5

RT

6:10

RA

11:15

RB

16:20

310

21:30

/

31

 

Format X-form

Opcode 0x7C00026C

Extension Base

Operands

• RT
  Target
• RA
  Base
• RB
  Index

Example

eciwx r3, r4, r5

Related

More in Base

Reference

View in PowerISA v3.1C Specification ↗ OPF Power ISA v3.1C

Description

Loads a 32-bit word from an external control device into RT, using address formation from RA + RB and device selection from the External Address Register (EAR). This instruction requires special external interface hardware support and does not affect condition registers. It is typically used in embedded or specialized processor configurations.

Operation

EA ← (RA) + (RB)
RT ← ExternalLoad32(EA, EAR)