No. 6650-9/12

LC72314W, 72315W, 72316W

Continued from preceding page.

Pin No.

Pin

I/O

Function

I/O circuit

System reset input.

In CPU operating mode or halt mode, applications must apply a low level for at least

one full machine cycle to reset the system and restart execution with the PC set to

location 0. This pin is connected in parallel with the internal power on reset circuit.

72

RES

I

Output for the 3 V step-up circuit clock. Outputs 1/2 the AM local oscillator frequency

in AM reception mode, and 1/256 the FM local oscillator or 75 kHz in FM reception

mode.

38

VDC1

O

Voltage stepped up by the DC-DC converter (3 V)

May also be used to input an equivalent voltage.

37

VDC3

I

RAM backup power supply. Connected to the VDC3 voltage through a diode.

36

VDDRAM

I

VDC3 voltage adjustment pin. Insert a 10 k

Ω variable resistor between this pin and

ground to adjust the VDC3 voltage.

39

VADJ

O

FM VCO (local oscillator) input.

This pin is selected with the PLL instruction CW1.

The input must be capacitor coupled.

Input is disabled in backup mode, in halt mode, after a reset, and in PLL stop mode.

75

FMIN

I

CMOS amplifier input

AM VCO (local oscillator) input.

This pin and the bandwidth are selected with the PLL instruction CW1.

The input must be capacitor coupled.

Input is disabled in backup mode, in halt mode, after a reset, and in PLL stop mode.

76

AMIN

I

CMOS amplifier input

Dedicated input port for the universal counter.

• For frequency measurement, select the HCTR frequency measurement mode and

measurement time with a UCS instruction (b3 = 0, b2 = 0) and start the counter with

a UCC instruction.

When the count operation completes, the CNTEND flag will be set. Since it operates

as an AC amplifier in this mode, the input must be provided through a coupling

capacitor.

Input is disabled in backup mode, HALT mode, after a reset, and in PLL STOP mode.

73

HCTR

I

CMOS amplifier input

Main charge pump output. When the local oscillator frequency divided by N is higher

than the reference frequency a high level is output, when lower, a low level is output,

and the pin is set to the high-impedance state when the frequencies match.

This output goes to the high-impedance state in backup mode, in halt mode, after a

reset, and in PLL stop mode.

78

EO

O

Power supply pin.

This pin must be connected to ground.

This pin must be connected to ground.

—

77

35

74

—

CMOS push-pull

CW1 b1, b0

Input pins

Bandwidth

1

0

AMIN (H)

2 to 20 MHz (SW)

1

1

FMIN (L)

0.5 to 10 MHz (MW, LW)

UCS b3, b2

Input pin measurement mode

0

0

HCTR frequency measurement

0

1

—

1

1

—

UCS b1, b0

Measurement time

0

0

1 ms

0

1

4 ms

1

0

8 ms

1

1

32 ms

Note*: When a pin in an I/O switching port is used as an output, applications must first set up the data with an OUT, SPB, or RPB instruction and then set up

output mode with an IOS instruction.