ht82k74e Holtek Semiconductor Inc., ht82k74e Datasheet - Page 41

• Manufacturer Part Number: ht82k74e
• Description: 27mhz Keyboard/ Mouse Tx 8-bit Mcu
• Manufacturer: Holtek Semiconductor Inc.

CPL [m]
Description
Operation
Affected flag(s)
CPLA [m]
Description
Operation
Affected flag(s)
DAA [m]
Description
Operation
Affected flag(s)
DEC [m]
Description
Operation
Affected flag(s)
DECA [m]
Description
Operation
Affected flag(s)
HALT
Description
Operation
Affected flag(s)
Rev. 1.00
Complement Data Memory
Each bit of the specified Data Memory is logically complemented (1 s complement). Bits
which previously contained a 1 are changed to 0 and vice versa.
[m]
Z
Complement Data Memory with result in ACC
Each bit of the specified Data Memory is logically complemented (1 s complement). Bits
which previously contained a 1 are changed to 0 and vice versa. The complemented result
is stored in the Accumulator and the contents of the Data Memory remain unchanged.
ACC
Z
Decimal-Adjust ACC for addition with result in Data Memory
Convert the contents of the Accumulator value to a BCD ( Binary Coded Decimal) value re-
sulting from the previous addition of two BCD variables. If the low nibble is greater than 9 or
if AC flag is set, then a value of 6 will be added to the low nibble. Otherwise the low nibble
remains unchanged. If the high nibble is greater than 9 or if the C flag is set, then a value of
6 will be added to the high nibble. Essentially, the decimal conversion is performed by add-
ing 00H, 06H, 60H or 66H depending on the Accumulator and flag conditions. Only the C
flag may be affected by this instruction which indicates that if the original BCD sum is
greater than 100, it allows multiple precision decimal addition.
[m]
[m]
[m]
[m]
C
Decrement Data Memory
Data in the specified Data Memory is decremented by 1.
[m]
Z
Decrement Data Memory with result in ACC
Data in the specified Data Memory is decremented by 1. The result is stored in the Accu-
mulator. The contents of the Data Memory remain unchanged.
ACC
Z
Enter power down mode
This instruction stops the program execution and turns off the system clock. The contents
of the Data Memory and registers are retained. The WDT and prescaler are cleared. The
power down flag PDF is set and the WDT time-out flag TO is cleared.
TO
PDF
TO, PDF
ACC + 00H or
ACC + 06H or
ACC + 60H or
ACC + 66H
[m]
0
[m]
1
[m]
[m]
1
1
41
HT82K74E/HT82K74EE
December 15, 2009