oris

OR Immediate Shifted

oris RA, RS, UI

Performs a bitwise OR with a 16-bit immediate shifted left by 16 bits.

Details

The OR Immediate instruction performs a bitwise OR operation between the contents of register RS and an immediate value formed by concatenating 480 with UI, and places the result into register RA.

Pseudocode Operation

RA <- RS | (UI || 0x0000)

Programming Note

The oris instruction is commonly used to set specific bits in a register by ORing it with an immediate value. Be cautious of overflow if UI exceeds the upper limit, as it will be truncated. This instruction operates at user privilege level and does not generate exceptions under normal circumstances.

Example

oris r3, r4, 0xFFFF

Encoding

Binary Layout
25
0
RS
6
RA
11
UI
16
 
Format D-form
Opcode 0x64000000
Extension Base

Operands

  • RA
    Target Register
  • RS
    Source Register
  • UI
    Unsigned 16-bit Immediate