beautypg.com

Texas Instruments MSP50C614 User Manual

Page 115

background image

Instruction Classification

4-23

Assembly Language Instructions

Table 4–11. Symbols and Explanation (Continued)

Symbol

Explanation

next A

Accumulator control bits as described in Table 4–6.

[

next A]

The preincrement (++A) or predecrement (– –A) operation on accumulator pointers A

n or An~.

Not

NOT condition on conditional jumps, conditional calls or test flag instructions.

n

R

Value in the repeat counter loaded by repeat instruction.

n

s

Value in string register STR.

offset[n]

n bit offset from a reference register.

pma[n]

n bit program memory address. For example, pma8 means 8-bit program memory address. If n
is not specified, defaults to pma16.

port[n]

n bit I/O port address.

R

R

x registers are treated as general purpose registers. These bits are not related to any addres-

sing modes.

R

x

Indirect register bits as described in Table 4–3.

s

Represents string mode if 1, otherwise normal mode.

x

Don’t care

Instructions on the MSP50P614/MSP50C614 are classified based on the op-
erations the instruction group performs (see Table 4–11). Each instruction
group is referred to as a class. There are 9 instruction classes. Classes are
subdivided into subclasses. Classes and opcode definitions are shown in
Table 4–11.

Table 4–11.

Instruction Classification

Class

Sub-
Class

Description

1

Accumulator and memory reference instructions

A

Accumulator and memory references with or without string operations and accumulator
preincrementing

B

Accumulator and memory references with or without string operations

2

Accumulator constant reference

A

Short constant to accumulator

B

Long constant to accumulator

3

Accumulator reference instructions with no addressing modes