M34551 View Datasheet(PDF) - MITSUBISHI ELECTRIC
Part Name
Description
Manufacturer
M34551
MITSUBISHI ELECTRIC
M34551 Datasheet PDF : 68 Pages
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MITSUBISHI MICROCOMPUTERS
4551 Group
SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER for
INFRARED REMOTE CONTROL TRANSMITTER
MULTIFUNCTION
Pin
Multifunction
Pin
Multifunction
D5
INT
INT
D5
D6
XCIN
XCIN
D6
D7
XCOUT
XCOUT
D7
P20
SEG16
SEG16
P20
P21
SEG17
SEG17
P21
P22
SEG18
SEG18
P22
P23
SEG19
SEG19
P23
Notes 1: Pins except above have just single function.
2: The port D5 is the output port and ports P20–P23 are the input ports.
CONNECTIONS OF UNUSED PINS
Pin
Connection
Pin
Connection
D0–D4
Connect to VSS, or set the output latch to CARR
Open
D5/INT
“0” and open.
SEG0–SEG15
Open
D6/XCIN
Select ports D6 and D7 and connect to VSS, COM0–COM3
Open
D7/XCOUT
or set the output latch to “0” and open. P00–P03
Set the output latch to “1” and open.
P 2 0 / S E G 1 6 – P 2 3 / Select port P2 and connect to VSS, or select P10–P13
Open or connect to VSS (Note)
SEG19
the segment output function and open.
Note: In order to connect ports P10–P13 to VSS, turn off their pull-up transistors (Pull-up control register PU0i=“0”) by software. In
order to make these pins open, turn on their pull-up transistors (register PU0i=“1”) by software, or turn off their pull-up
transistors (register PU0i=“0”) and set the output latch to “0” (i = 0, 1, 2, or 3).
Be sure to select the key-on wakeup function and the pull-up function with every one port.
(Note in order to set the output latch to “0” and make pins open)
• After system is released from reset, a port is in a high-impedance state until the output latch of the port is set to “0” by software.
Accordingly, the voltage level of pins is undefined and the excess of the supply current may occur.
• To set the output latch periodically is recommended because the value of output latch may change by noise or a program run away
(caused by noise).
(Note in order to connect unused pins to VSS or VDD)
• To avoid noise, connect the unused pins to VSS or VDD at the shortest distance using a thick wire.
PORT FUNCTION
Port
Pin
Port D
Port P0
D0–D4, D5/INT,
D6/XCIN,
D7/XCOUT
P00–P03
Port P1 P10–P13
Port P2
P20/SEG16–
P23/SEG19
Input/
Output
Output
(8)
I/O
(4)
I/O
(4)
Input
(4)
Output structure
N-channel open-drain
N-channel open-drain
N-channel open-drain
Control Control Control
bits instructions registers
1 SD
MR
RD
CLD
4 OP0A
IAP0
4 OP1A
PU0
IAP1
4 IAP2
Remark
Pull-up functions
Key-on wakeup functions
Pull-up functions
(programmable)
Key-on wakeup functions
(programmable)
5
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