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Rev. 2.50
82
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Rev. 2.50
83
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HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
Input/Output Ports
Holtek microcontrollers offer considerable flexibility on their I/O ports. With the input or output
designation of every pin fully under user program control, pull-high selections for all ports and
wake-up selections on certain pins, the user is provided with an I/O structure to meet the needs of a
wide range of application possibilities.
The device provides bidirectional input/output lines labeled with port names PA~PG. These I/O
ports are mapped to the RAM Data Memory with specific addresses as shown in the Special Purpose
Data Memory table. All of these I/O ports can be used for input and output operations. For input
operation, these ports are non-latching, which means the inputs must be ready at the T2 rising edge
of instruction "MOV A,[m]", where m denotes the port address. For output operation, all the data is
latched and remains unchanged until the output latch is rewritten.
I/O Port Register List
•
HT66F20
Register
Name
Bit
7
6
5
4
3
2
1
0
PAWU
D�
D6
D5
D4
D3
D2
D�
D0
PAPU
D�
D6
D5
D4
D3
D2
D�
D0
PA
D�
D6
D5
D4
D3
D2
D�
D0
PAC
D�
D6
D5
D4
D3
D2
D�
D0
PBPU
—
—
D5
D4
D3
D2
D�
D0
PB
—
—
D5
D4
D3
D2
D�
D0
PBC
—
—
D5
D4
D3
D2
D�
D0
PCPU
—
—
—
—
D3
D2
D�
D0
PC
—
—
—
—
D3
D2
D�
D0
PCC
—
—
—
—
D3
D2
D�
D0
•
HT66F30
Register
Name
Bit
7
6
5
4
3
2
1
0
PAWU
D�
D6
D5
D4
D3
D2
D�
D0
PAPU
D�
D6
D5
D4
D3
D2
D�
D0
PA
D�
D6
D5
D4
D3
D2
D�
D0
PAC
D�
D6
D5
D4
D3
D2
D�
D0
PBPU
—
—
D5
D4
D3
D2
D�
D0
PB
—
—
D5
D4
D3
D2
D�
D0
PBC
—
—
D5
D4
D3
D2
D�
D0
PCPU
D�
D6
D5
D4
D3
D2
D�
D0
PC
D�
D6
D5
D4
D3
D2
D�
D0
PCC
D�
D6
D5
D4
D3
D2
D�
D0