HCS512

DS40151C-page 4

© 1997 Microchip Technology Inc.

2.0

PIN ASSIGNMENT

PIN

Decoder

Function

Buffer

Description

1

LRNIN

I

TTL

Learn input - initiates learning, 10K pull-up required on input

2

LRNOUT

O

TTL

Learn output - indicates learning

3

NC

—

TTL

Do not connect

4

MCLR

I

ST

Master clear input

5

Ground

P

—

Ground connection

6

S0

O

TTL

Switch 0

7

S1

O

TTL

Switch 1

8

S2

O

TTL

Switch 2

9

S3

O

TTL

Switch 3

10

Vlow

O

TTL

Battery low indication output

11

SLEEP

I

TTL

Connect to RFIN to allow wake-up from sleep

12

CLK

I/O

Clock in programming mode and synchronous mode

13

DATA

I/O

Data in programming mode and synchronous mode

14

P

—

Power connection

15

—

—

Oscillator out – no connection

16

I

ST

Oscillator in – recommended values 10 k

Ω and 10pF

17

NC

—

—

18

RFIN

I

TTL

RF input from receiver

Note 1: P = power, I = in, O = out, and ST = Schmitt Trigger input.

2: Pin 12 and Pin 13 have a dual purpose. After reset, these pins are used to determine if programming mode

is selected in which case they are the clock and data lines. In normal operation, they are the clock and data

lines of the synchronous data output stream.