–

–

–

–

4

5

Pin Assignments

Figure 6: MS Series Deccoder Pin Assignments

Pin Descriptions

Pin Number

Name

I/O

Description

1, 2, 13, 14, 17–20

DO–D7

O

Data Output Lines. These

lines reproduce the state of

the encoder's data lines upon

reception of a valid packet.

3

SEL_BAUD0

I

Baud Rate Selection Line 0. This

line along with SEL_BAUD1 sets

the baud rate of the serial data

stream to one of 4 possible rates.

The rate must be set before power

on.

4

SEL_BAUD1

I

Baud Rate Selection Line 1. This

line along with SEL_BAUD0 sets

the baud rate of the serial data

stream to one of 4 possible rates.

The rate must be set before power

on.

5, 6

GND

Ground

7

LATCH

I

Set Latched Outputs. If this line

is low, then the data outputs are

momentary (active for as long

as a valid signal is received). If

this line is high, the outputs are

latched (when a signal is received

to make a particular data line

high, it remains high until another

transmission is received instructing

it to go low).

8

RX_CNTL

I/O

External Receiver Control

Line. This line can be used to

automatically power on and off

a receiver. It powers the receiver

down for ten times as long as

it is powered on. The times are

determined by the selected baud

rate.

Figure 7: Pin Descriptions

D6

D7

SEL_BAUD0

SEL_BAUD1

GND

GND

LATCH

RX_CNTL

TX_ID

MODE_IND

D5

D4

D3

D2

VCC

VCC

D1

D0

DATA_IN

LEARN

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

LICAL-DEC-MS001

9

TX_ID

O

Transmitter ID Output Line.

A unique ID number for each

transmitter is stored in the

decoder’s memory. A byte is

output as serial data on this line

to indicate which transmitter a

transmission came from.

10

MODE_IND

O

Mode Indicator Output. This line

switches when a valid transmission

is received, when Learn Mode is

entered, and when the memory

is cleared. This allows for the

connection of a LED to indicate

to the user that these events have

taken place.

11

LEARN

I

Learn Mode Activation Line. When

this line goes high, the decoder

enters Learn Mode to accept an

Address from an encoder and

store it in memory. If it is held high

for ten seconds, the decoder

clears all stored Addresses from

memory.

12

DATA_IN

I

Data Input Line. This line accepts

the encoded serial data stream

from a receiver.

15, 16

V

CC

Supply Voltage

None of the input lines have internal pull-up or pull-down resistors. The input lines must

always be in a known state (either GND or V

be predictable. The designer must ensure that the input lines are never floating, either

by using external resistors, by tying the lines directly to GND or V

circuits to control the line state.