dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 678

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

Once extension and alignment is done, a 20- or 36-bit calculation is performed, and the result is stored
based on the destination size that is encoded in the opcode.
AGU operations are always performed using 24-bit quantities, and they always generate 24-bit results.
Logic in the AGU automatically extends operands that are smaller than 24 bits in size, based on the type of
operand specified. Figure B-2 shows the rules for extension based on the type of operand that is specified.
B-2
5-Bit Immediate Operands
8-Bit Operands
32-Bit Operands
36-Bit Operands
16-Bit Operands
20-Bit Operands
24-Bit Operands
4-Bit Immediate Operands
6-Bit Immediate Operands
16-Bit Immediate Operands
16-Bit Register Operands
17-Bit Immediate Operands
Figure B-1. Internal Data ALU Alignment and Extension
Figure B-2. Internal AGU Alignment and Extension
DSP56800E Core Reference Manual
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Sign Extension
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Zero Fill
Zero Fill
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