eciwx

External Control In Word Indexed

eciwx RT, RA, RB

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

Details

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.

Pseudocode Operation

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

Example

eciwx r3, r4, r5

Encoding

Binary Layout
31
0
RT
6
RA
11
RB
16
310
21
/
31
 
Format X-form
Opcode 0x7C00026C
Extension Base

Operands

  • RT
    Target
  • RA
    Base
  • RB
    Index