HT49C50 datasheet(39/52 Pages) HOLTEK

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CPLA [m]

Complement data memory and place result in the accumulator

Description

Each bit of the specified data memory is logically complemented (1¢s comple-

ment). Bits which previously contained a one are changed to zero and

vice-versa. The complemented result is stored in the accumulator and the

contents of the data memory remain unchanged.

Operation

ACC ¬ [m]

Affected flag(s)

TC2 TC1

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DAA [m]

Decimal-Adjust accumulator for addition

Description

The accumulator value is adjusted to the BCD (Binary Code Decimal) code.

The accumulator is divided into two nibbles. Each nibble is adjusted to the

BCD code and an internal carry (AC1) will be done if the low nibble of the ac-

cumulator is greater than 9. The BCD adjustment is done by adding 6 to the

original value if the original value is greater than 9 or a carry (AC or C) is set;

otherwise the original value remains unchanged. The result is stored in the

data memory and only the carry flag (C) may be affected.

Operation

If ACC.3~ACC.0 >9 or AC=1

then [m].3~[m].0 ¬ (ACC.3~ACC.0)+6, AC1=AC

else [m].3~[m].0) ¬ (ACC.3~ACC.0), AC1=0

and

If ACC.7~ACC.4+AC1 >9 or C=1

then [m].7~[m].4 ¬ ACC.7~ACC.4+6+AC1,C=1

else [m].7~[m].4 ¬ ACC.7~ACC.4+AC1,C=C

Affected flag(s)

TC2 TC1

¾¾¾¾¾

DEC [m]

Decrement data memory

Description

Data in the specified data memory is decremented by one.

Operation

[m] ¬ [m]-1

Affected flag(s)

TC2 TC1

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HT49C50

August 18, 1999

HT49C50 Scheda tecnica(PDF) 39 Page - Holtek Semiconductor Inc

HT49C50 Scheda tecnica(HTML) 39 Page - Holtek Semiconductor Inc

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