Pop Alias; Dsp56800 Instruction Set Summary; Register Field Notation; Table 6-12 Clear Instruction Alias - Motorola DSP56800 Manual

Instruction Set Introduction
Operation
CLR
6.5.5

POP Alias

The POP instruction operates identically to a move from the stack with post-decrement. When the
assembler encounters the POP instruction in a program, it assembles a
instruction in its place. If POP does not specify a destination register, it is assembled as
Table 6-13. Move Word Instruction Alias—Data Memory
Operation
POP
6.6

DSP56800 Instruction Set Summary

This section presents the entire DSP56800 instruction set in tabular form. The tables provide a quick
reference to the entire instruction set because they show not only the instructions themselves, but also the
registers, addressing modes, cycle counts, and program words required for each instruction. From these
tables, it is very easy to determine if a particular operation can be performed with a desired register or
addressing mode.
The summary, found in Section 6.6.3, "Instruction Summary Tables," is based on logical groupings of
instructions, listing the instructions alphabetically within each grouping. This summary also contains the
number of program words required by the instruction as well as the number of cycles required for
execution.
This section contains the following information:
• Usage of the instruction summary tables
• Addressing mode notation
•

Register field notation

• The instruction summary tables
6.6.1 Register Field Notation
There are many different register fields used within the instruction summary tables. These will be grouped
into sets that are more easily understood.
Table 6-14 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 (src), and the
other where it is used as a destination (dst). This is important because a different notation is used when an
accumulator is being stored without saturation. Also see the register fields in Table 6-15, which are also
used in move instructions as sources and destinations within the AGU.
6-14
Table 6-12. Clear Instruction Alias
Destination
X0, Y1, Y0, Identical to
A1, B1, codes
R0–R3, N
Source Destination
(Any register)
(None specified)
DSP56800 Family Manual
Comments
MOVE #0,<register>
MOVE (SP)-,<register>
Comments
Pop a single stack location
Simply decrements the SP
; does not set condition
.
LEA (SP)-