Evaluation Kit User Manual for FX828 and FX829

EV8000

© 2004 CML Microsystems Plc

14

UM8000/4

1.6

Detailed Description

1.6.1

Hardware Description - Signalling Processor Board

1.6.1.1 Operating Voltage

Jumper JP1 is used to select the operating voltage. Open circuit selects 5.0V operation (default)

and closed circuit (link fitted) selects 3.3V operation.

1.6.1.2 Clock/Oscillator

The evaluation devices may use either an external clock or their own xtal oscillator. A 4.032MHz

xtal is provided on-board for the latter method. The links on jumpers JP2 and JP3, which are

normally fitted, select the xtal oscillator. An external clock may be supplied to JP3 pin 1 once the

links have been removed.

1.6.1.3 Microphone

By fitting a link to jumper JP7, the on-board electret microphone is connected via a buffer amplifier

to the MICIN input of the FX829. The signal applied to the FX829 can be monitored

at TP8. A push-to-talk (PTT) switch is also provided.

1.6.1.4 Loudspeaker

An 8

Ω loudspeaker output is provided at the 3.5mm mono jack socket J5. The signal source for

the loudspeaker can be either the FX829 (default) or the FX8x8, link selectable at jumper JP6.

1.6.1.5 C-BUS and optional level shifting.

There are identical connectors (J1 and J2) either side of the board for C-BUS. This enables the

C-BUS source to be connected either side of the signalling processor board and also enables

future C-BUS evaluation boards to be connected in parallel. A third connector (J3) allows the

daisy chaining of a second signalling processor board with alternative /IRQ and /CS lines. This

allows for the emulation of both ends of a radio link, using a single PC.

processor board. Level shifting can be added to the C-BUS interface by removing solder links

LK4 to LK7 and fitting the following components:

A 74F07 in position U5.

A pull-up resistor pack in position RP1, suggested value 470

Ω.

A pull-up resistor in position R22, suggested value 22k

Ω.

A de-coupling capacitor for U5 may be fitted in position C22, suggested value 47nF.

1.6.1.6 Analogue re-configuration

Some discrete components and links around the target devices are socketed to allow path gains

to be adjusted. Also the analogue connector J6 has a second bare footprint, J7, which, in

conjunction with the removable components and links, can be used as a patch board to allow the

user to re-arrange signal paths as required.

The current consumption of the FX829 or the FX828 may be measured by removing the link on

jumper JP4 or JP5 respectively and replacing it with a multimeter.