Instruction Classification

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

 

 

cc

 

 

cc names

Description

 

 

 

 

 

 

 

 

 

 

 

 

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

 

 

 

 

 

 

 

 

 

4.4.8Class 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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Assembly Language Instructions

4-41

Page 127
Image 127
Texas Instruments MSP50C6xx manual Class 8 Instructions Logic and Bit, Class 8a Instruction Encoding