ecowx

External Control Out Word Indexed

ecowx RS, RA, RB

Stores a word to an external device using the EAR register.

Encoding

Binary Layout

31

0:5

RS

6:10

RA

11:15

RB

16:20

438

21:30

/

31

 

Format X-form

Opcode 0x7C00036C

Extension Base

Operands

• RS
  Source
• RA
  Base
• RB
  Index

Example

ecowx r3, r4, r5

Related

More in Base

Reference

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

Description

Stores a 32-bit word from RS to an external control device, 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)
ExternalStore32(EA, EAR, (RS))