4554 Datasheet, PDF (8/138 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4554 Group
CONNECTIONS OF UNUSED PINS
Pin
XIN
XOUT
Connection
Connect to VSS.
Open.
XCIN
XCOUT
D0–D6
D7/CNTR0
D8/INT0
D9/INT1
C/CNTR1
P00–P03
Connect to VSS.
Open.
Open.
Connect to VSS.
Open.
Connect to VSS.
Open.
Connect to VSS.
Open.
Connect to VSS.
Open.
Open.
Connect to Vss.
P10–P13
Open.
Connect to Vss.
SEG31/P20–
SEG28/P23
SEG27/P30–
SEG24/P33
COM0–COM3
SEG0/VLC3
SEG1/VLC2
SEG2/VLC1
SEG3–SEG23
Open.
Connect to Vss.
Open.
Connect to Vss.
Open.
Open.
Open.
Open.
Open.
Usage condition
Internal oscillator is selected (CMCK and CRCK instructions are not executed.)
(Note 1)
Sub-clock input is selected for system clock (MR0=1). (Note 2)
Internal oscillator is selected (CMCK and CRCK instructions are not executed.)
(Note 1)
RC oscillator is selected (CRCK instruction is executed)
External clock input is selected for main clock (CMCK instruction is executed).
(Note 3)
Sub-clock input is selected for system clock (MR0=1). (Note 2)
Sub-clock is not used.
Sub-clock is not used.
External clock input is selected for sub-clock.
(Note 4)
N-channel open-drain is selected for the output structure.
CNTR0 input is not selected for timer 1 count source.
N-channel open-drain is selected for the output structure.
“0” is set to output latch.
“0” is set to output latch.
CNTR1 input is not selected for timer 3 count source.
The key-on wakeup function is not selected. (Note 4)
N-channel open-drain is selected for the output structure. (Note 5)
The pull-up function is not selected. (Note 4)
The key-on wakeup function is not selected. (Note 4)
The key-on wakeup function is not selected. (Note 4)
N-channel open-drain is selected for the output structure. (Note 5)
The pull-up function is not selected. (Note 4)
The key-on wakeup function is not selected. (Note 4)
Ports P20–P23 selected.
Ports P30–P33 selected.
SEG0 pin is selected.
SEG1 pin is selected.
SEG2 pin is selected.
Notes 1: When the CMCK and CRCK instructions are not executed, the internal oscillation (on-chip oscillator) is selected for main clock.
2: When sub-clock (XCIN) input is selected (MR0 = 1) for the system clock by setting “1” to bit 1 (MR1) of clock control register MR, main clock is stopped.
3: Select the ceramic resonance by executing the CMCK instruction to use the external clock input for the main clock.
4: Be sure to select the output structure of ports D0–D6 and the pull-up function and key-on wakeup function of P00–P03 and P10–P13 with every one
port. Set the corresponding bits of registers for each port.
5: Be sure to select the output structure of ports P00–P03 and P10–P13 with every two ports. If only one of the two pins is used, leave another one open.
(Note when connecting to VSS and VDD)
q Connect the unused pins to VSS and VDD using the thickest wire at the shortest distance against noise.
Rev.3.00 Aug 06, 2004 page 8 of 136
REJ03B0043-0300Z