HMS87C5216 Datasheet, PDF (29/76 Pages) List of Unclassifed Manufacturers – CMOS SINGLE-CHIP 8-BIT MICROCONTROLLER FOR UR(Universal Remocon) & WIRELESS KEYBOARD

HMS87C5216
10. I/O PORTS
The GMS87C5216 has 38 I/O ports which are PORT0(8 I/O),
PORT1 (8 I/O), PORT2 (8 I/O), PORT3 (8 I/O), PORT4 (6 I/O).
Pull-up resistor of each port can be selectable by program. Each
port contains data direction register which controls I/O and data
register which stores port data
10.1 R0 Ports
R0 is an 8-bit CMOS bidirectional I/O port (address 0C0_H). Each
I/O pin can independently used as an input or an output through
the R0DD register (address 0C1_H).
R0 has internal pull-ups that is independently connected or dis-
connected by R0PC. The control registers for R0 are shown be-
low.
R0 Data Register (R/W)
ADDRESS : 0C0_H
RESET VALUE : Undefined
R0
R07 R06 R05 R04 R03 R02 R01 R00
R0 Direction Register (W)
R0DD
ADDRESS : 0C1_H
RESET VALUE : 00_H
Port Direction
0: Input
1: Output
R0 Pull-up Selection Register (W)
R0PC
ADDRESS :0F8_H
RESET VALUE : 00_H
Pull-up select
1: Without pull-up
0: With pull-up
R0 Open drain Assign Register (W)
ADDRESS :0E4_H
RESET VALUE : 00_H
R0ODC
Open drain select
0: Push-pull
1: Open drain
(1) R0 I/O Data Direction Register (R0DD)
R0 I/O Data Direction Register (R0DD) is 8-bit register, and can
assign input state or output state to each bit. If R0DD is ``1``, port
R0 is in the output state, and if ``0``, it is in the input state. R0DD
is write-only register. Since R0DD is initialized as ``00 h`` in re-
set state, the whole port R0 becomes input state.
(2) R0 Data Register (R0)
R0 data register (R0) is 8-bit register to store data of port R0.
When set as the output state by R0DD, and data is written in R0,
data is outputted into R0 pin. When set as the input state, input
state of pin is read. The initial value of R0 is unknown in reset
state.
(3) R0 Open drain Assign Register (R0ODC)
R0 Open Drain Assign Register (R0ODC) is 8bit register, and can
assign R0 port as open drain output port each bit, if corresponding
port is selected as output. If R0ODC is selected as ``1``, port R0
is open drain output, and if selected as ``0``, it is push-pull output.
R0ODC is write-only register and initialized as ``00 h`` in reset
state.
(4) R0 Pull-up Resistor Control Register (R0PC)
R0 pull-up resistor control register (R0PC) is 8-bit register and
can control pull-up on or off each bit, if corresponding port is se-
lected as input. If R0PC is selected as ``1``, pull-up ia disabled
and if selected as ``0``, it is enabled. R0PC 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.
10.2 R1 Ports
R1 is an 8-bit CMOS bidirectional I/O port (address 0C2_H). Each
I/O pin can independently used as an input or an output through
the R1DD register (address 0C3_H).
R1 has internal pull-ups that is independently connected or dis-
connected by register R1PC. The control registers for R1 are
shown below.
SEP. 2004 Ver 1.01