Arithmetic Instructions - Motorola DSP56156 Manual

Each instruction group is described in the following sections. Detailed information on each
instruction is given in Appendix A of the DSP56100 Family Manual .
1.7.1.1

Arithmetic Instructions

The arithmetic instructions perform all of the arithmetic operations within the Data ALU.
They may affect all of the condition code register bits. Arithmetic instructions are register-
based (register direct addressing modes used for operands) so that the Data ALU opera-
tion indicated by the instruction does not use the XDB or the GDB. Optional data transfers
may be specified with most arithmetic instructions. This allows for parallel data movement
over the XDB and over the GDB during a Data ALU operation. This allows new data to be
prefetched for use in following instructions and results calculated by previous instructions
to be stored. These instructions execute in one instruction cycle. The following are the
arithmetic instructions.
ABS Absolute Value
ADC Add Long with Carry*
ADD Add †
ASL Arithmetic Shift Left
ASL4 4 Bit Arithmetic Shift Left*
ASR Arithmetic Shift Right
ASR4 4 Bit Arithmetic Shift Right*
ASR16 16 Bit Arithmetic Shift Right*
CHKAAU Update the V, Z, N flags according to the address calculation result*
CLR Clear an Accumulator
CLR24 Clear 24 MSBs of an Accumulator
CMP Compare
CMPM Compare Magnitude
DEC Decrement Accumulator
DEC24 Decrement upper word of Accumulator
DIV Divide Iteration*
DMAC Double (Multi) precision oriented MAC*
EXT Sign Extend Accumulator from bit 31*
IMAC Integer Multiply-Accumulate*
IMPY Integer Multiply*
INC Increment Accumulator
INC24 Increment 24 MSBs of Accumulator
MAC Signed Multiply-Accumulate †
MACR Signed Multiply-Accumulate and Round †
MPY Signed Multiply †
MPYR Signed Multiply and Round †
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INSTRUCTION SET SUMMARY
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