GMS81C2020/GMS81C2120
Hyundai Micro Electronics
(address C6H). Each port can be set individually as input
and output through the R3IO register (address C7H).
0
1
R00 (Normal I/O Port)
R00/
INT0
INT0 (External interrupt 0 Input
Port)
Each port can directly drive a vacuum fluorescent display..
ADDRESS : C6H
R3 Data Register
RESET VALUE : Undefined
12.3 R1 and R1IO registers
-
-
R3
R35 R34 R33 R32 R31 R30
INPUT / OUTPUT DATA
R1 is an 8-bit high-voltage CMOS bidirectional I/O port
(address C2H). Each port can be set individually as input
and output through the R1IO register (address C3H). Each
port can directly drive a vacuum fluorescent display..
ADDRESS : C7H
RESET VALUE : --000000
R3 Direction Register
R3IO
ADDRESS : C2H
R1 Data Register
RESET VALUE : Undefined
R1
R17 R16 R15 R14 R13 R12 R11 R10
DIRECTION SELECT
0 : INPUT PORT
1 : OUTPUT PORT
INPUT / OUTPUT DATA
ADDRESS : C3H
RESET VALUE : 00000000
Figure 12-5 Registers of Port R3
R1 Direction Register
R1IO
12.6 R4 and R4IO registers
R4 is an 4-bit bidirectional I/O port (address C8H). Each
port can be set individually as input and output through the
R4IO register (address C9H).
DIRECTION SELECT
0 : INPUT PORT
1 : OUTPUT PORT
R40 port is multiplexed with Timer 0 Output Port(T0O), r
Figure 12-3 Registers of Port R1
ADDRESS : C8H
RESET VALUE : Undefined
R4 Data Register
12.4 R2 and R2IO registers
R4
-
-
-
-
R43 R42 R41 R40
INPUT / OUTPUT DATA
R2 is an 8-bit high-voltage CMOS bidirectional I/O port
(address C4H). Each port can be set individually as input
and output through the R2IO register (address C5H). Each
port can directly drive a vacuum fluorescent display..
ADDRESS : C9H
RESET VALUE : ----0000
R4 Direction Register
R4IO
ADDRESS : C4H
R2 Data Register
RESET VALUE : Undefined
R2
R27 R26 R25 R24 R23 R22 R21 R20
INPUT / OUTPUT DATA
DIRECTION SELECT
0 : INPUT PORT
1 : OUTPUT PORT
R4 Function Selection Register
R4FUNC
ADDRESS : F5H
RESET VALUE : -------0
ADDRESS : C5H
R2 Direction Register
R2IO
RESET VALUE : 00000000
-
-
-
-
-
-
-
T0O
0 : R40
1 : T0O
DIRECTION SELECT
0 : INPUT PORT
1 : OUTPUT PORT
Figure 12-6 Registers of Port R4
The control register R4FUNC (address F5H) controls to se-
lect 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
Figure 12-4 Registers of Port R2
12.5 R3 and R3IO registers
R1 is an 6-bit high-voltage CMOS bidirectional I/O port
44
preliminary
Nov. 1999 Ver 0.0
HYNIX [ HYNIX SEMICONDUCTOR ]
