HMS81C2012A Datasheet, PDF (41/107 Pages) List of Unclassifed Manufacturers – CMOS Single-Chip 8-Bit Microcontroller with A/D Converter & VFD Driver

HMS81C2012A/2020A
R1 and R0IO register: R1 is an 8-bit high-voltage CMOS
bidirectional I/O port (address 0C2_H). Each port can be set
individually as input and output through the R1IO register
(address 0C3_H). Each port can directly drive a vacuum flu-
orescent display.
R1 Data Register
ADDRESS: 0C2_H
RESET VALUE: Undefined
R1
R17 R16 R15 R14 R13 R12 R11 R10
Input / Output data
R1 Direction Register
R1IO
ADDRESS : 0C3_H
RESET VALUE : 00_H
Port Direction
0: Input
1: Output
R2 and R2IO register: R2 is an 8-bit high-voltage CMOS
bidirectional I/O port (address 0C4_H). Each port can be set
individually as input and output through the R2IO register
(address 0C5_H). Each port can directly drive a vacuum flu-
orescent display.
R2 Data Register
ADDRESS: 0C4_H
RESET VALUE: Undefined
R2
R27 R26 R25 R24 R23 R22 R21 R20
Input / Output data
R2 Direction Register
R2IO
ADDRESS : 0C5_H
RESET VALUE : 00_H
Port Direction
0: Input
1: Output
R3 and R3IO register: R3 is a 6-bit high-voltage CMOS
bidirectional I/O port (address 0C6_H). Each port can be set
individually as input and output through the R3IO register
(address 0C7_H).
R3 Data Register
ADDRESS: 0C6_H
RESET VALUE: Undefined
R3
- - R35 R34 R33 R32 R31 R30
Input / Output data
R3 Direction Register
R3IO ^{- -}
ADDRESS : 0C7_H
RESET VALUE : --000000_B
Port Direction
0: Input
1: Output
R4 and R4IO register: R4 is a 4-bit bidirectional I/O port
(address 0C8_H). Each port can be set individually as input
and output through the R4IO register (address 0C9_H). R40
port is multiplexed with Timer 0 Output Port (T0O).
Port Pin
R40
Alternate Function
T0O (Timer 0 Compare Output Port)
The control register R4FUNC (address 0F5_H) controls to
select alternate function. After reset, this value is "0", port
may be used as general I/O ports. To select alternate func-
tion such as Timer 0 Output, write "1" to the corresponding
bit of R4FUNC. Regardless of the direction register R4IO,
R4FUNC is selected to use as alternate functions, port pin
can be used as a corresponding alternate features (T0O)
R4 Data Register
R4
---
ADDRESS: 0C8_H
RESET VALUE: Undefined
- R43 R42 R41 R40
Input / Output data
R4 Direction Register
R4IO ^{- - - -}
ADDRESS : 0C9_H
RESET VALUE : ----0000_B
Port Direction
0: Input
1: Output
R4
Function
Selection
Register
ADDRESS : 0F5_H
RESET VALUE : -------0_B
R4FUNC - - - - - - - T0O
0: R40
1: T0O
SEP. 2004 Ver 2.00
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