A.1 Notation; Table A-1 Register Fields For General-Purpose Writes And Reads - Motorola DSP56800 Manual

Appendix A
Instruction Set Details
This appendix contains detailed information about each instruction of the DSP56800 instruction set. It
contains sections on notation, addressing modes, and condition codes. Also included is a section on
instruction timing, which shows the number of program words and execution time of each instruction.
Finally, the instruction set summary, which shows the syntax of all allowed DSP56800 instructions, is
presented.
A.1 Notation
Each instruction description contains notation used to abbreviate certain operands and operations. The
symbols and their respective descriptions are listed in Table A-1 through Table A-7 on page A-4.
Table A-1 shows the register set available for the most important move instructions. Sometimes the
register field is broken into two different fields—one where the register is used as a source and the other
where it is used as a destination. This is important because a different notation is used when an
accumulator is being stored without saturation. In addition, see the register fields in Table A-2 on
page A-2, which are also used in move instructions as sources and destinations within the AGU.
Table A-1. Register Fields for General-Purpose Writes and Reads
Register Field Registers in This Field
HHH
HHHH
DDDDD
R0, R1, R2, R3
A, B, A1, B1 Seven data ALU registers — two accumulators, two 16-bit MSP por-
X0, Y0, Y1 tions of the accumulators and three 16-bit data registers
A, B, A1, B1 Seven data ALU and five AGU registers
X0, Y0, Y1
R0-R3, N
A, A2, A1, A0 All CPU registers
B, B2, B1, B0
Y1, Y0, X0
N, SP
M01
OMR, SR
LA, LC
HWS
Instruction Set Details
Comments
A-1