HMS87C5216 ETC1 [List of Unclassifed Manufacturers], HMS87C5216 Datasheet - Page 31

• Manufacturer Part Number: HMS87C5216
• Description: CMOS SINGLE-CHIP 8-BIT MICROCONTROLLER FOR UR(Universal Remocon) & WIRELESS KEYBOARD
• Manufacturer: ETC1 [List of Unclassifed Manufacturers]

(1) R2 I/O Data Direction Register (R2DD)
R2 I/O Data Direction Register (R2DD) is 8-bit register, and can
SEP. 2004 Ver 1.01
R2 Data Register (R/W)
R2
R2 Direction Register (W)
R2DD
R2 Pull-up Selection Register (W)
R2PC
R2 Open drain Assign Register (W)
R2ODC
R27 R26 R25 R24 R23 R22 R21 R20
ADDRESS : 0C4
RESET VALUE : Undefined
ADDRESS : 0C5
RESET VALUE : 00
ADDRESS :0FA
RESET VALUE : 00
ADDRESS :0DF
RESET VALUE : 00
Port Direction
0: Input
1: Output
Pull-up select
1: Without pull-up
0: With pull-up
Open drain select
0: Push-pull
1: Open drain
H
H
H
H
H
H
H
assign input state or output state to each bit. If R2DD is ``1``, port
R2 is in the output state, and if ``0``, it is in the input state. R2DD
is write-only register. Since R2DD is initialized as ``00 h`` in re-
set state, the whole port R2 becomes input state.
(2) R2 Data Register (R2)
R2 data register (R2) is 8-bit register to store data of port R2.
When set as the output state by R2DD, and data is written in R2,
data is outputted into R2 pin. When set as the input state, input
state of pin is read. The initial value of R2 is unknown in reset
state.
(3) R2 Open drain Assign Register (R2ODC)
R2 Open Drain Assign Register (R2ODC) is 8bit register, and can
assign R2 port as open drain output port each bit, if corresponding
port is selected as output. If R2ODC is selected as ``1``, port R2
is open drain output, and if selected as ``0``, it is push-pull output.
R2ODC is write-only register and initialized as ``00 h`` in reset
state.
(4) R2 Pull-up Resistor Control Register (R2PC)
R2 pull-up resistor control register (R2PC) is 8-bit register and
can control pull-up on or off each bit, if corresponding port is se-
lected as input. If R2PC is selected as ``1``, pull-up ia disabled
and if selected as ``0``, it is enabled. R2PC is write-only register
and initialized as ``00 h`` in reset state. The pull-up is automati-
cally disabled, if corresponding port is selected as output.
HMS87C5216