Casio 130CR Service Manual page 16

(2) Non-port pins (2/2)
Pin Name I/O
AD0 to AD7 I/O Lower address/data bus when expanding memory
externally
A8 to A15 Output Higher address bus when expanding memory
externally
RD Output Strobe signal output for read operation from external
memory
WR Strobe signal output for write operation to external
memory
WAIT Input Wait insertion when accessing external memory
ASTB Output Strobe output externally latching address information
output to ports 4 and 5 to access external memory
ANI0 to ANI7 Input A/D converter analog input
ANO0, ANO1 Output D/A converter analog output
AV Input A/D converter reference voltage input (also functions
REF0
as analog power supply)
AV Input D/A converter reference voltage input
REF1
AV — A/D converter, D/A converter ground potential. Use
SS
the same potential as V
RESET Input System reset input
X1 Input Crystal connection for main system clock oscillation
X2 —
XT1 Input Crystal connection for subsystem clock oscillation
XT2 —
V — Positive power supply for ports
DD0
V — Ground potential for ports
SS0
V — Positive power supply (except ports and analog
DD1
block)
V — Ground potential (except ports and analog block)
SS1
V — High-voltage application for program write/verify.
PP
IC — Internally connected. Connect directly to V
Function
.
SS0
.
SS0
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After Reset Alternate Function
Input P40 to P47
Input P50 to P57
Input P64
P65
Input P66
Input P67
Input P10 to P17
Input P130, P131
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Input P07
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