dsp56000 Freescale Semiconductor, Inc, dsp56000 Datasheet - Page 460

• Manufacturer Part Number: dsp56000
• Description: 24-bit Digital Signal Processor Family Manual
• Manufacturer: Freescale Semiconductor, Inc

Class II Example:
Explanation of the Class II Example: Prior to execution, the 24-bit registers, X0 and
Y0, contain $400000 and $600000, respectively. The 56-bit accumulators A and B con-
tain the values $00:000000:000000 and $00:800000:000000 (+1.0000), respectively.
The 24-bit Y memory location Y:$1234 contains the value $000000, and the 16-bit R1
register contains the value $1234. Execution of the parallel move portion of the instruc-
tion (Y0,B B,Y:(R1)+) moves the Y0 register ($600000) into accumulator B1 ($600000),
sign extends B1 into B2 ($00), and zero fills B0 ($000000). It also moves the 24-bit lim-
ited value of B ($7FFFFF) into the Y:$1234 memory location and increments R1 to
$1235.
A - 194
R:Y
Y:$1234
MAC X0,Y0,A
X0
Y0
R1
A
B
:
:
Before Execution
$00:000000:000000
$00:800000:000000
Y0,B
Freescale Semiconductor, Inc.
For More Information On This Product,
Register and Y Memory Data Move
INSTRUCTION DESCRIPTIONS
$400000
$600000
$000000
INSTRUCTION SET DETAILS
$1234
B,Y:(R1)+
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Y:$1234
;move B to Y memory location pointed to
;by R1 and postincrement R1
;move Y0 to B
;multiply X0 and Y0 and accumulate in A
R1
X0
Y0
A
B
After Execution
$00:300000:000000
$00:600000:000000
$7FFFFF
$400000
$600000
$1235
MOTOROLA
R:Y