HT47C20L datasheet(49/55 Pages) HOLTEK

49 / 55 page

SBC A,[m]

Subtract data memory and carry from accumulator

Description

The contents of the specified data memory and the complement of the

carry flag are together subtracted from the accumulator, leaving the re-

sult in the accumulator.

Operation

ACC ¬ ACC+[m]+C

Affected flag(s)

TC2 TC1

ÖÖÖÖ

SBCM A,[m]

Subtract data memory and carry from accumulator

Description

The contents of the specified data memory and the complement of the

carry flag are together subtracted from the accumulator, leaving the re-

sult in the data memory.

Operation

[m] ¬ ACC+[m]+C

Affected flag(s)

TC2 TC1

¾¾

ÖÖÖÖ

SDZ [m]

Skip if decrement data memory is zero

Description

The contents of the specified data memory are decremented by one. If the

result is zero, the next instruction is skipped. If the result is zero, the fol-

lowing instruction, fetched during the current instruction execution, is

discarded and a dummy cycle replaced to get the proper instruction. This

makes a 2-cycle instruction. Otherwise proceed with the next instruc-

tion.

Operation

Skip if ([m]-1)=0, [m] ¬ ([m]-1)

Affected flag(s)

TC2 TC1

¾¾¾¾¾¾

HT47C20L

January 18, 2000

HT47C20L Datasheet(PDF) 49 Page - Holtek Semiconductor Inc