
Rev. 1.21
54
�ove��e� ��� 2�1�
Rev. 1.21
55
�ove��e� ��� 2�1�
HT66F488/HT66F489
A/D Flash MCU with EEPROM
HT66F488/HT66F489
A/D Flash MCU with EEPROM
Register
Reset
(Power On)
WDT Time-out
(Normal Operation)
LVR Reset
WDT Time-out
(HALT)
TXR/RXR
x x x x x x x x
x x x x x x x x
x x x x x x x x
u u u u u u u u
SLCDC�
� � � � � � � �
� � � � � � � �
� � � � � � � �
u u u u u u u u
SLCDC1
� � � � � � � �
� � � � � � � �
� � � � � � � �
u u u u u u u u
SLCDC2
� � � � � � � �
� � � � � � � �
� � � � � � � �
u u u u u u u u
SLCDC3
� � � � � � � �
� � � � � � � �
� � � � � � � �
u u u u u u u u
SLCDC4
� � � � � � � �
� � � � � � � �
� � � � � � � �
u u u u u u u u
Note: "-" not implement
"u" stands for "unchanged"
"x" stands for "unknown"
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~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
PAWU
PAWU�
PAWU6
PAWU5
PAWU4
PAWU3
PAWU2
PAWU1
PAWU�
PAPU
PAPU�
PAPU6
PAPU5
PAPU4
PAPU3
PAPU2
PAPU1
PAPU�
PA
PA�
PA6
PA5
PA4
PA3
PA2
PA1
PA�
PAC
PAC�
PAC6
PAC5
PAC4
PAC3
PAC2
PAC1
PAC�
PBPU
PBPU�
PBPU6
PBPU5
PBPU4
PBPU3
PBPU2
PBPU1
PBPU�
PB
PB�
PB 6
PB 5
PB4
PB3
PB2
PB1
PB�
PBC
PBC�
PBC6
PBC5
PBC4
PBC3
PBC2
PBC1
PBC�
PCPU
PCPU�
PCPU6
PCPU5
PCPU4
PCPU3
PCPU2
PCPU1
PCPU�
PC
PC�
PC6
PC5
PC4
PC3
PC2
PC1
PC�
PCC
PCC�
PCC6
PCC5
PCC4
PCC3
PCC2
PCC1
PCC�
PDPU
—
—
PDPU5
PDPU4
PDPU3
PDPU2
PDPU1
PDPU�
PD
—
—
PD5
PD4
PD3
PD2
PD1
PD�
PDC
—
—
PDC5
PDC4
PDC3
PDC2
PDC1
PDC�
I/O Control Register List
PAPUn, PBPUn, PCPUn, PDPUn
: I/O Port Pull-High Control
0: Disable
1: Enable
PAWUn
: I/O Port A bit 7 ~ bit 0 Wake Up Control
0: Disable
1: Enable
PACn, PBCn, PCCn, PDCn
: I/O Port Input/Output Control
0: Output
1: Input