dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 528

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

MOVE.B
Operation:
S → D
Description: Move an 8-bit value from a register to memory or from memory to a register. Register-indirect memory
Example 1:
Explanation of Example:
Example 2:
Explanation of Example:
A-184
Before Execution
Before Execution
(no parallel move)
A2
0
locations are specified with word pointers, offsets are specified as byte offsets, and absolute addresses
are specified as byte addresses. Register operands are affected as follows:
– If the source operand is a 16-bit register, the lower 8 bits are moved.
– If the destination operand is a 16-bit register, the lower 8 bits are written and the upper 8 bits are
– If the source operand is an accumulator, the lower 8 bits of FF1 are moved.
– If the destination operand is an accumulator, the lower 8 bits of FF1 are written, FF2 and the upper
– If the destination operand is the Y register, the lower 8 bits of Y1 are written, the upper 8 bits of Y1
MOVE.B
Prior to the memory move, the accumulator register A contains the value $0:6677:8899. After execu-
tion of the MOVE.B X:(R0+$21),A instruction, the FF1 portion of A is updated with the value in
memory that is pointed to by the word pointer R0, with a byte offset of $21, which results in the upper
byte of the word memory X:$4454. The results is sign extended through bit 35 of A. The FF0 portion
of A is filled with zero. The content of the A accumulator becomes $F:FF90:0000.
MOVE.B
Prior to execution, the word location X:$1111 contains the value $3333. After execution of the
MOVE.B X:(R0+$20),X:$2223 instruction, the lower byte of the word memory location pointed
to by (R0+$20), which is location X:$4454, is written to the upper byte of the word memory location
X:$1111, which is specified as X:$2223 in byte address. The value at X:$1111 becomes $6033.
filled with sign extension.
8 bits of FF1 are filled with sign extension, and FF0 is zero filled.
are filled with sign extension, and Y0 is zero filled.
6677
R0
R0
X:$4454
X:$4454
X:$1111
A1
X:(R0+$21),A
X:(R0+$20),X:$2223 ; move byte from memory into memory
Move Byte (Word Pointer)
004444
004444
DSP56800E Core Reference Manual
9060
3333
8899
9060
A0
; move byte from memory into A
Assembler Syntax:
MOVE.B
After Execution
After Execution
A2
F
S,D
R0
R0
FF90
X:$4454
X:$1111
X:$4454
A1
(no parallel move)
Freescale Semiconductor
004444
004444
MOVE.B
0000
9060
9060
6033
A0