dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 551

• Manufacturer Part Number: dsp56800e
• Description: 16-bit Digital Signal Controller Core
• Manufacturer: Freescale Semiconductor, Inc

MOVEU.B
Operation:
S → D
Description: Move an 8-bit value from memory to a register or from one memory location to another. The source
Example 1:
Explanation of Example:
Example 2:
Explanation of Example:
Condition Codes Affected:
Freescale Semiconductor
Before Execution
Before Execution
(no parallel move)
A2
F
operand cannot be a register. Register-indirect memory locations are specified with word pointers, off-
sets are specified as byte offsets, and absolute addresses are specified as byte addresses. Register op-
erands are affected as follows:
– If the destination operand is a 16-bit register, the lower 8 bits are written and the upper 8 bits are
– If the destination operand is the Y register, the lower 8 bits of Y1 are written, and the upper 8 bits
– If the destination operand is an accumulator, the lower 8 bits of FF1 are written, the upper 8 bits of
MOVEU.B X:(R0+$21),A
Prior to the memory move, the accumulator register A contains the value $F:CCDD:2233. After exe-
cution of the MOVEU.B X:(R0+$21),A instruction, the low-order 8 bits of A1 are updated with the
value in memory that is pointed to by the word pointer R0, with a byte offset of $21, and the value is
zero extended through bit 35. The FF0 portion of A is zero filled. The value in the A accumulator be-
comes $0:0090:0000; R0 is unaffected.
MOVEU.B X:(SP),X0; move byte from memory into X0
Prior to the memory move, the accumulator register X0 contains the value $DDEE. After execution of
the MOVEU.B X:(SP),X0 instruction, the low-order 8 bits of X0 are updated with the value in
memory that is pointed to by the word pointer SP, and the value is zero extended through bit 15. The
X0 register becomes $0096; SP is unaffected.
The condition codes are not affected by this instruction.
filled with zero extension.
of Y1 and all of Y0 are filled with zero.
FF1 an FF2 are filled with zero extension, and FF0 is zero filled.
CCDD
R0
SP
X:$4454
X:$4443
A1
X0
004444
004443
Move Unsigned Byte
DDEE
2233
9060
6996
A0
Instruction Set Details
; move byte from memory into A
Assembler Syntax:
MOVEU.B
After Execution
After Execution
A2
0
S,D
R0
SP
0090
X:$4454
X:$4443
A1
(no parallel move)
X0
MOVEU.B
004444
004443
0000
9060
0096
6996
A0
A-207