GMS81508B HYNIX [Hynix Semiconductor], GMS81508B Datasheet - Page 35

• Manufacturer Part Number: GMS81508B
• Description: HYUNDAI MICRO ELECTRONICS 8-BIT SINGLE-CHIP MICROCONTROLLERS
• Manufacturer: HYNIX [Hynix Semiconductor]

GMS81508B/16B/24B
R3 and R3DD register: R3 is an 8-bit CMOS bidirection-
al I/O port (address 0C6
used as an input or an output through the R0DD register
(address 0C7
R4 and R4DD register: R4 is an 8-bit CMOS bidirection-
al I/O port (address 0C8
used as an input or an output through the R4DD register
(address 0C9
In addition, Port R4 is multiplexed with various special
features. The control register PMR4 (address 0D0
trols the selection of alternate function. After reset, this
value is “0”, port may be used as normal I/O port.
To use alternate function such as external interrupt, exter-
nal counter input or timer clock out, write “1” in the corre-
sponding bit of PMR4.
32
Port Pin
R3 Data Register
R3
R3 Direction Register
R3DD
R40
R41
R42
R43
R44
R45
R46
R47
H
R37 R36 R35 R34 R33 R32 R31 R30
H
).
).
INT0 (External Interrupt 0)
INT1 (External Interrupt 1)
INT2 (External Interrupt 2)
INT3 (External Interrupt 3)
EC0 (External count input to Timer/
Counter 0)
EC2 (External count input to Timer/
Counter 2)
T1O (Timer 1 Clock-out)
T3O (Timer 3 Clock-out)
H
H
). Each I/O pin can independently
). Each I/O pin can independently
Alternate Function
Input / Output data
Port Direction
0: Input
1: Output
ADDRESS: 0C6
RESET VALUE: Undefined
ADDRESS: 0C7
RESET VALUE: 00
H
H
H
H
) con-
Regardless of the direction register R4DD, PMR4 is select-
ed to use as alternate functions, port pin can be used as a
corresponding alternate features.
R4 Data Register
R4
R4 Port Mode Register
PMR4
Edge Selection Register
IEDS
R4 Direction Register
R4DD
R47 R46 R45 R44 R43 R42 R41 R40
7
7
INT3
External Interrupt Edge Select
00: Reserved
01: Falling (1-to-0 transition)
10: Rising (0-to-1 transition)
11: Both (Rising & Falling)
0: R47
1: T3O
6
6
0: R46
1: T1O
5
5
HYUNDAI MicroElectronics
INT2
0: R45
1: EC2
4
4
0: R44
1: EC0
3
3
INT1
Input / Output data
Port Direction
0: Input
1: Output
DEC. 1999 Ver 1.04
ADDRESS: 0C8
RESET VALUE: Undefined
ADDRESS: 0D0
RESET VALUE: 00
ADDRESS: 0C9
RESET VALUE: 00
2
2
ADDRESS: 0F8H
RESET VALUE: 00H
0: R43
1: INT3
1
1
INT0
0: R42
1: INT2
0
0
0: R41
1: INT1
H
H
H
0: R40
1: INT0
H
H