Rev. 1.50
64
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Rev. 1.50
65
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HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
HT66F0175/HT66F0185
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.
These devices provide bidirectional input/output lines labeled with port names PA~PD. 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.
Register
Name
Bit
7
6
5
4
3
2
1
0
P�WU
P�WU�
P�WU6
P�WU5
P�WU4
P�WU3
P�WU�
P�WU1
P�WU0
P�
P��
P�6
P�5
P�4
P�3
P��
P�1
P�0
P�C
P�C�
P�C6
P�C5
P�C4
P�C3
P�C�
P�C1
P�C0
P�PU
P�PU�
P�PU6
P�PU5
P�PU4
P�PU3
P�PU�
P�PU1
P�PU0
PB
—
PB6
PB5
PB4
PB3
PB�
PB1
PB0
PBC
—
PBC6
PBC5
PBC4
PBC3
PBC�
PBC1
PBC0
PBPU
—
PBPU6
PBPU5
PBPU4
PBPU3
PBPU�
PBPU1
PBPU0
PC
—
PC6
PC5
PC4
PC3
PC�
PC1
PC0
PCC
—
PCC6
PCC5
PCC4
PCC3
PCC�
PCC1
PCC0
PCPU
—
PCPU6
PCPU5
PCPU4
PCPU3
PCPU�
PCPU1
PCPU0
I/O Registers List – HT66F0175