upd64a Renesas Electronics Corporation., upd64a Datasheet - Page 16

• Manufacturer Part Number: upd64a
• Description: 4-bit Single-chip Microcontroller For Infrared Remote Control Transmission
• Manufacturer: Renesas Electronics Corporation.

3.2 K
3.2.1 K
3.2.2 S
using bit 4 of the P4 register.
not flow internally. In OFF mode, “1” can be read regardless of the pin state.
3.2.3 S
and output mode.
using bit 4 of the P4 register.
transmission display pin (refer to 4. TIMER).
16
The K
The pin state can be read.
Use of a pull-down resistor for the K
After reset, a pull-down resistor is connected.
b
b
b
b
Caution In order to prevent malfunction, do not input a high level to all the K
The S
The pin state can be read by setting this port to input mode with bit 0 of the P4 register.
In input mode, use of a pull-down resistor for the S
If input mode is released (thus set to OFF mode), the pin becomes high impedance but through current does
After reset, this port is set to OFF mode, thus becoming high impedance.
The S
Bit 2 of the P4 register can be used to set input or output mode. The pin state can be read in both input mode
In input mode, use of a pull-down resistor for the S
In output mode, the pull-down resistor is automatically disconnected, and this pin becomes the remote control
After reset, this port enters output mode, and a high level is output.
1
2
3
4
:
:
:
to b
I
I
0
1
Port/Special Port (P1)
I
0
1
/LED port (bit 3 of P1)
port (P
7
/LED port is an I/O port.
port (bit 2 of P1)
port is a 4-bit input port for key entry.
: The state of the K
port is an input/OFF mode port.
The state of the S
In input mode, the state of the S
In OFF mode, this bit is fixed to 1.
The state of the S
released due to supply voltage startup (these pins can be left open. When leaving open, keep
pull-down resistors connected).
Bit
Name
11
: bits 4 to 7 of P1)
b
K
2
1
I
7
I3
/LED pin is read regardless of input/output mode (read only).
pin is read (read only).
pin is read (read only).
Table 3-3. K
I
b
K
port can be specified in 4-bit units by software using bit 5 of the P4 register.
6
I2
Data Sheet U14380EJ3V0DS00
0
pin is read (read only).
b
K
I
5
I1
/Special Port Register (P1)
0
0
and S
and S
b
K
4
I0
1
1
/LED ports can be specified in 2-bit units by software
/LED ports can be specified in 2-bit units by software
b
S
3
1
/LED
b
S
2
0
b
S
1
2
I0
to K
Fixed to “1”
b
I3
0
pins when POC is
PD64A, 65