dsp56000 Freescale Semiconductor, Inc, dsp56000 Datasheet - Page 37

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

3.2.3 Data ALU A and B Accumulators
The Data ALU features two general-purpose, 56-bit accumulators, A and B. Each con-
sists of three concatenated registers (A2:A1:A0 and B2:B1:B0, respectively). The 8-bit
sign extension (EXT) is stored in A2 or B2 and is used when more than 48-bit accuracy is
needed; the 24-bit most significant product (MSP) is stored in A1 or B1; the 24-bit least
MOTOROLA
ACCUMULATOR A
24 BITS
48 BITS
56 BITS
OVERVIEW AND DATA ALU ARCHITECTURE
Freescale Semiconductor, Inc.
H
R
S
F
T
E
I
For More Information On This Product,
DATA ARITHMETIC LOGIC UNIT
CONVERGENT - ROUNDING
Go to: www.freescale.com
Figure 3-3 MAC Unit
Y0, OR Y1
FORCING FUNCTION
X0,X1,
24-BITx24-BIT
FRACTIONAL
MULTIPLIER
+
–
Y0, OR Y1
X0,X1,
CODE GENERATOR
CONDITION
ARITHMETIC AND
ACCUMULATOR B
LOGIC UNIT
MODE BITS
SCALING
56 - BIT
R
24
Y0, OR Y1
X0,X1,
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