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Texas Instruments MSP50C6xx User Manual

Page 127

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Instruction Classification

4-41

Assembly Language Instructions

Table 4–31. Class 7 Instruction Encoding and Description (Continued)

cc

cc names

Description

cc

cc name

Not cc name

1

0

1

0

1

Unconditional

1

0

1

1

0

Not assigned

1

0

1

1

1

Not assigned

1

1

0

0

0

XZ

XNZ

Conditional on XSF

1

1

0

0

1

XS

XNS

Conditional on XZF

1

1

0

1

0

XG

XNG

Conditional on ! XSF and ! XZF

1

1

0

1

1

Not assigned

1

1

1

0

0

Not assigned

1

1

1

0

1

Not assigned

1

1

1

1

0

Not assigned

1

1

1

1

1

Not assigned

4.4.8

Class 8 Instructions: Logic and Bit

This class of instructions provides a flexible and efficient means to make
complex logical decisions. Instead of making a sequence of single bit
decisions and constructing a logical statement through a branch decision tree,
the program can sequentially combine several status conditions to directly
construct a final logic value (TF1 or TF2) which can be used to control a
subsequent branch or call. This class includes two subclasses. Class 8a
instructions update one of the test flags (TF1 or TF2) with a logical combination
of the old test flag value and an addressed memory flag value. Subclass 8b
provides a flexible means of logically combining the test flag (TF1 or TF2) with
a status condition and storing the results back to the test flag.

Table 4–32. Class 8a Instruction Encoding

Bit

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Class 8a

1

0

0

1

1

flg

Not

C8a

flagadrs

Class 8b

1

0

0

1

0

flg

Not

cc

Rx

C8b

RFLAG {flagadrs}

1

0

0

1

1

0

0

0

1

1

flagadrs

SFLAG {flagadrs}

1

0

0

1

1

1

0

1

0

1

flagadrs