HT66F25D View Datasheet(PDF) - Holtek Semiconductor
Part Name
Description
MFG CO.
'HT66F25D' PDF : 177 Pages View PDF
A/D Flash Type 8-bit MCU with EEPROM
HT66F24D/HT66F25D
Pull-high Resistors
Many product applications require pull-high resistors for their switch inputs usually requiring the
use of an external resistor. To eliminate the need for these external resistors, all I/O pins, when
configured as an input have the capability of being connected to an internal pull-high resistor. These
pull-high resistors are selected using registers PAPU~PDPU and are implemented using weak
PMOS transistors.
PAPU Register
Bit
7
Name PAWU7
R/W
R/W
POR
0
6
PAWU6
R/W
0
5
PAWU5
R/W
0
4
PAWU4
R/W
0
3
PAWU3
R/W
0
2
PAWU2
R/W
0
Bit 7~0
PAWU7~PAWU0: I/O Port A bit 7 ~ bit 0 Pull-high Control
0: Disable
1: Enable
1
PAWU1
R/W
0
0
PAWU0
R/W
0
PBPU Register
• HT66F24D
Bit
7
Name
—
R/W
—
POR
—
6
5
4
3
2
1
0
—
PBPU5 PBPU4 PBPU3 PBPU2 PBPU1 PBPU0
—
R/W
R/W
R/W
R/W
R/W
R/W
—
0
0
0
0
0
0
• HT66F25D
Bit
7
Name PBPU7
R/W
R/W
POR
0
6
PBPU6
R/W
0
5
PBPU5
R/W
0
4
PBPU4
R/W
0
PBPUn:
“—”: Unimplemented, read as 0
I/O Port B bit n Pull-high Control
0: Disable
1: Enable
3
PBPU3
R/W
0
2
PBPU2
R/W
0
1
PBPU1
R/W
0
0
PBPU0
R/W
0
PCPU Register
• HT66F24D/HT66F25D
Bit
7
6
Name PCPU7 PCPU6
R/W
R/W
R/W
POR
0
0
5
PCPU5
R/W
0
4
PCPU4
R/W
0
PCPUn:
“—”: Unimplemented, read as 0
I/O Port C bit n Pull-high Control
0: Disable
1: Enable
3
PCPU3
R/W
0
2
PCPU2
R/W
0
1
PCPU1
R/W
0
0
PCPU0
R/W
0
Rev. 1.10
61
March 25, 2013
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