GMS81004 Datasheet, PDF (35/101 Pages) Hynix Semiconductor – 8-BIT SINGLE CHIP MICROCOMPUTERS

Chapter 3. I/O PORT
3.2.3 Data Register(R1)
R1 Data Register(R1) is 8-bit register to store data of port R1. When set as the output
state by R1DD, and data is written in R1, data is output into R1 pin.
The initial value of R1 is unknown in reset state.
bit
7
6
5
4
3
2
1
0
R1
R17
R16
R15
R14
R13
R12
R11
R10
<00C2H>
initial value
X
X
X
X
X
X
X
X
R/W ^R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
3.2.4 Port R1 Open drain Assign Register (R1ODC)
bit
7
6
5
4
3
2
1
0
R1ODC R17OD R16OD R15OD R14OD R13OD R12OD R11OD R10OD <00DEH>
initial value
0
0
0
0
0
0
0
0
R/W
W
W
W
W
W
W
W
W
Port R1 Open Drain Assign Register(R1ODC) is 8bit register, and can assign R1 port as
open drain output port each bit, if corresponding port is selected as output. If R1ODC is
selected as ¡È1¡È, port R1 is open drain output, and if selected as¡È0¡È, it is push-pull
output. R1ODC is write-only register and initialized as ¡È00H¡È in reset state.
3 -3