Spreadsheet Conventions

ALTD (“A” Column) Symbol Key

Flag

f

fr

r

s

Description

ALTD selects alternate flags

ALTD selects alternate flags and register

ALTD selects alternate register

ALTD operation is a special case

IOI and IOE (“I” Column) Symbol Key

Flag

Description

 

 

bIOI and IOE affect source and destination

dIOI and IOE affect destination

sIOI and IOE affect source

 

 

 

Flag Register Key

 

 

 

 

S Z

L/V*

C

Description

*

 

 

Sign flag affected

 

 

 

 

-

 

 

Sign flag not affected

*Zero flag affected

-Zero flag not affected

LLV flag contains logical check result

VLV flag contains arithmetic overflow result

0LV flag is cleared

*LV flag is affected

*Carry flag is affected

-Carry flag is not affected

0Carry flag is cleared

1Carry flag is set

*The L/V (logical/overflow) flag serves a dual purpose— L/V is set to 1 for logical operations if any of the four most significant bits of the result are 1, and L/V is reset to 0 if all four of the most significant bits of the result are 0.

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Rabbit 3000 Microprocessor

Page 257
Image 257
Jameco Electronics 2000, 3000 manual Spreadsheet Conventions, Flag Description