Pin Functions
Number
Name
I/O
26
IN1
25
IN2
I
24
RQ
23
SI
22
ACK
21
SO
20
OUT3
O
19
WE
18
CE2
17
OUT2
LC7041
Equivalent circuit
Description
Low-threshold input ports. Built-in 100kΩ (typ) pull-down resistance.
Input is prohibited when HOLD is LOW.
Main microcontroller serial communications request signal.
Main microcontroller serial communications data input signal.
Main microcontroller serial communications ack-
nowledge signal.
Main microcontroller serial communications
data output signal.
General-purpose output port.
RAM write enable signal.
Input is prohibited
when HOLD is LOW.
RAM control signal.
General-purpose output port.
16 to 9
D0 to D7
I
ROM and RAM data input pins. Input is prohibited when HOLD is LOW.
6 to 4
3
8
7
32 to 49
27
28
29
30
31
51
50
57
58
IN3 to IN5
I
INT
SCK
O
OUT4
A17 to A0
OUT5
OUT1
O
CE1
CE
OE
COM1
O
COM2
FMIN
I
AMIN
General-purpose input ports. Input is prohibited when HOLD is LOW.
Processor intterrupt input. Valid for LOW-level pulses of 10 µs or longer.
Interrupts are prohibited during backup mode.
Main microcontroller serial communications clock signal. N-channel
open-drain, high-voltage port for use with a pull-up resistor. High
impedance when HOLD goes LOW.
General-purpose output port. N-channel open-drain, high-voltage port for
use with a pull-up resistor. High impedance when HOLD goes LOW.
ROM and RAM address signal.
General-purpose output ports.
ROM and RAM control signals.
Input is prohibited
when HOLD is LOW.
–
Leave open for normal use.
FM VCO input. Capacitively couple for normal use.
AM VCO input. Capacitively couple for normal use.
54
HCTR
I
IF counter input. Capacitively couple for normal use. 0.4 to 12MHz input
frequency.
Continued on next page.
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