SAB80C517-M16 SIEMENS [Siemens Semiconductor Group], SAB80C517-M16 Datasheet - Page 195

• Manufacturer Part Number: SAB80C517-M16
• Description: 8-Bit CMOS Single-Chip Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Operation:
Encoding:
Bytes:
Cycles:
Semiconductor Group
BCD variables can be incremented or decremented by adding 01 H or 99 H . If the
accumulator initially holds 30 H (representing the digits of 30 decimal), then the
instruction sequence
ADD
DA
will leave the carry set and 29 H in the accumulator, since 30 + 99 = 129. The low-
order byte of the sum can be interpreted to mean 30 – 1 = 29.
DA
contents of accumulator are BCD
if [[(A3-0) > 9]
then (A3-0)
and
if [[(A7-4) > 9]
then (A7-4)
1
1
1 1 0 1
A, #99H
A
0 1 0 0
(A3-0) + 6
(A7-4) + 6
[(AC) = 1]]
[(C) = 1]]
196
Instruction Set