LC872G08A_10 Datasheet, PDF (10/27 Pages) Sanyo Semicon Device – 8K/6K/4K-byte ROM and 256-byte RAM integrated 8-bit 1-chip Microcontroller

LC872G08A/06A/04A
Recommended Unused Pin Connections
Port Name
P00 to P07
P10 to P17
P20 to P21
P70
CF1/XT1
CF2/XT2
Recommended Unused Pin Connections
Board
Open
Open
Open
Open
Pulled low with a 100kΩ resistor or less
Pulled low with a 100kΩ resistor or less
Software
Output low
Output low
Output low
Output low
General-purpose input port
General-purpose input port
Notes on CF1/XT1 and CF2/XT2 pins
• When using as general-purpose input ports
Since the CF1/XT1 and CF2/XT2 pins are configured as CF oscillator pins at system reset time, it is necessary to
add a current limiting resistor of 1kΩ or greater to the CF2/XT2 pin in series when using them as general-purpose
input pins.
• Differences between flash and mask ROM version
System Reset Time State
Flash ROM version
LC87F2G08A
CF1/XT1
CF2/XT2
Set high via the internal Rf resistor
Set high
Mask ROM version
LC872G08A/06A/04A
CF1/XT1
CF2/XT2
Set low via the internal Rf resistor
Set low
After System Reset is Released
CF oscillation state
CF oscillation state
CF oscillation state
CF oscillation state
Power Pin Treatment Recommendations (VDD1, VSS1)
Connect bypass capacitors that meet the following conditions between the VDD1 and VSS1 pins:
• Connect among the VDD1 and VSS1 pins and bypass capacitors C1 and C2 with the shortest possible heavy lead
wires, making sure that the impedances between the both pins and the bypass capacitors are as equal as possible
(L1=L1’, L2=L2’).
• Connect a large-capacity capacitor C1 and a small-capacity capacitor C2 in parallel.
The capacitance of C2 should be approximately 0.1μF.
L2
L1
C1
C2
VSS1
L1’
L2’
VDD1
No.A1400-10/27