dsp56000 Freescale Semiconductor, Inc, dsp56000 Datasheet - Page 418

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

Timing: 2+mv oscillator clock cycles
Memory: 1+mv program words
Example 2:
Explanation of Example 2: The content of X0 ($654321) is multiplied by 2
added to the content of the A accumulator ($00:100000:000000). The result is then
placed in the A accumulator. The net effect of this operation is to divide the content of
X0 by 2
right shifted 3 places and filled with the sign bit (0 for a positive number and 1 for a neg-
ative number) and then the result is added to the accumulator.
Instruction Format 2:
Opcode 2:
Instruction Fields:
A - 152
MAC
MAC
MAC
S
Y1
X0
Y0
X1
3
0
23
and add the result to the accumulator. An alternate interpretation is that X0 is
X0
A
X0,
:
:
Q Q
0 0
0 1
1 0
1 1
0
( )S,#n,D
0
0
#3, A
$00:100000:000000
Before Execution
0
Sign
Freescale Semiconductor, Inc.
+
–
0
For More Information On This Product,
$654321
0
INSTRUCTION DESCRIPTIONS
INSTRUCTION SET DETAILS
Signed Multiply-Accumulate
1
0
1
16 15
k
Go to: www.freescale.com
0
0
D
A
B
;
0
s
0
1
d
s
X0
A
s
s
s
8
$00:1CA864:200000
After Execution
7
1
1
$654321
Q
Q
d
k
MOTOROLA
MAC
-3
1
and then
0
0