User Manual

14. USING THE DEVELOPER’S KIT
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LZT 123 7589 R1A
DIS - When fitted, the serial port driver IC disables the
receiver buffers that normally drive UART signals into
the radio device. This will prevent the radio device
from receiving data through the serial port.
WAKE - When fitted, the radio device will automatically
power-up when the UART DTR signal is driven high.
This allows a convenient mechanism for an external
host computer to switch on the module. The DTR
signal must be driven low or negative before the
module can be switched off under software
command.
Note: If DTR is not driven low or negative and the host
computer commands the module to shut-down, the
DTR signal in its high state will immediately indicate
that the module is to switch back on.
BAUD - When fitted, this jumper allows the serial port driver IC
to operate at baud rates in excess of 250 kbps and
up to 1 Mbps.
Note: There will be an increase in current
consumption with this option selected.
SHDN - When fitted, the serial port IC is forced into a low
power state with the internal transmitters disabled. In
the shut-down state the radio device will still receive
commands but any transmission attempts from the
radio device will be blocked by the serial port IC.
Notes:
In the shut-down state all the hardware flow control
transmitters will be switched off. In order to send
commands to the radio device in this state, the host
computer must also have hardware flow control
switched off.
There is a second jumper labelled ’SHDN’ which is in
the Power Supply area (adjacent to U7).
Jumper Default Description