GMS81C2012/GMS81C2020
HYUNDAI MicroElectronics
R1 and R0IO register: R1 is an 8-bit high-voltage CMOS
bidirectional I/O port (address 0C2H). Each port can be set
individually as input and output through the R1IO register
(address 0C3H). Each port can directly drive a vacuum flu-
orescent display.
(address 0C7H).
R3 Data Register
ADDRESS: 0C6H
RESET VALUE: Undefined
-
-
R35 R34 R33 R32 R31 R30
R3
Input / Output data
ADDRESS: 0C2H
RESET VALUE: Undefined
R1 Data Register
R17 R16 R15 R14 R13 R12 R11 R10
R1
ADDRESS : 0C7H
RESET VALUE : --000000B
R3 Direction Register
Input / Output data
-
-
R3IO
Port Direction
0: Input
1: Output
ADDRESS : 0C3H
RESET VALUE : 00H
R1 Direction Register
R1IO
R4 and R4IO register: R4 is a 4-bit bidirectional I/O port
(address 0C8H). Each port can be set individually as input
and output through the R4IO register (address 0C9H). R40
port is multiplexed with Timer 0 Output Port (T0O).
Port Direction
0: Input
1: Output
R2 and R2IO register: R2 is an 8-bit high-voltage CMOS
bidirectional I/O port (address 0C4H). Each port can be set
individually as input and output through the R2IO register
(address 0C5H). Each port can directly drive a vacuum flu-
orescent display.
Alternate Function
Port Pin
R40
T0O (Timer 0 Compare Output Port)
The control register R4FUNC (address 0F5H) 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)
ADDRESS: 0C4H
RESET VALUE: Undefined
R2 Data Register
R27 R26 R25 R24 R23 R22 R21 R20
R2
Input / Output data
ADDRESS : 0C5H
RESET VALUE : 00H
R2 Direction Register
ADDRESS: 0C8H
RESET VALUE: Undefined
R4 Data Register
R2IO
-
-
-
-
R43 R42 R41 R40
R4
Port Direction
0: Input
Input / Output data
1: Output
ADDRESS : 0C9H
RESET VALUE : ----0000B
R3 and R3IO register: R3 is a 6-bit high-voltage CMOS
bidirectional I/O port (address 0C6H). Each port can be set
individually as input and output through the R3IO register
R4 Direction Register
-
-
-
-
R4IO
Port Direction
0: Input
1: Output
ADDRESS : 0F5H
RESET VALUE : -------0B
R4 Function Selection Register
-
-
-
-
-
-
-
T0O
R4FUNC
0: R40
1: T0O
40
MAR. 2000 Ver 1.00
HYNIX [ HYNIX SEMICONDUCTOR ]
