2.2.30 (1) EXTU (W)
EXTU (EXTend as Unsigned)
Zero Extension
Operation
0
→
(<bits 15 to 8> of Rd>)
Zero extend
Assembly-Language Format
EXTU.W
Rd
Operand Size
Word
Condition Code
H: Previous value remains unchanged.
N: Always cleared to 0.
Z: Set to 1 if the result is zero; otherwise
cleared to 0.
V: Always cleared to 0.
C: Previous value remains unchanged.
I
UI
H
U
N
Z
V
C
—
—
—
—
0
↕
0
—
Description
This instruction extends the lower 8 bits in a 16-bit register Rd to word data by padding with
zeros. That is, it clears the upper 8 bits of Rd (bits 15 to 8) to 0.
Available Registers
Rd: R0 to R7, E0 to E7
Operand Format and Number of States Required for Execution
Notes
Don’t care
Rd
8 bits
8 bits
Zero extension
Rd
8 bits
8 bits
Instruction Format
1st byte
2nd byte
3rd byte
4th byte
Register direct
EXTU.W
Rd
1
7
5
rd
2
No. of
States
Addressing
Mode
Mnemonic
Operands
100