Smart Com Radio Transceiver IC
RF600T
Dual Pin Functions
As shown in the pin function list above, a number of output pins have dual usage. During power up
they are briefly configured as inputs to allow the selection of system options as shown below. Note
that any load connected to these pins must not bias the RF600T pin such that the option setting
network is significantly disturbed.
In order to configure these pins it is recommended that they are connected as shown.
Vcc or GND
Vcc
1. Tie the relevant pin to Vcc or GND via
a 100K resistor. This is useful if the
option is permanently unselected.
100KΩ
100KΩ
2. Tie to Vcc or GND via a 100K resistor
and also add a jumper link and 2.2K
resistor to the other rail. This allows the
user to select the function of the pin by
insertion/removal of the link.
RF600T
Pin
RF600T
Pin
2.2KΩ
Pin
Number
Name
Type
Description
Function during power up:
Sets RF600T into ‘Loop back’ Mode (see below)
Disabled if connected to Vcc as shown above.
Enabled if connected to GND as shown above.
LOOP
CTS
In
3
Out
Function after power on:
Clear To Send control line to host (when low).
Function during power up:
Host Baud rate Select.
HBAUD
TxR
In
9600baud if connected to Vcc as shown above.
19200baud if connected to GND as shown above.
9
Out
Function after power on:
Transmit data to radio module..
Function during power up:
Controls the baud rate for the RF link.
400uS if connected to Vcc as shown above.
200uS if connected to GND as shown above.
RFBAUD
TXEN
In
10
Out
Function after power on:
Transmit enable (low) to radio module.
Learn pin (addressed mode only)
The learn pin is used both to sense the learn/erase switch and also to drive the indicator LED and should
be connected as shown in the application circuit. The switch, which should be of the normally open type,
should be connected from the learn pin to ground. The LED and its series current limiting resistor should
DS601-4
25th JUN 2004
©2004 Reg. No. 227 4001, ENGLAND
Page 4
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