EV8680 datasheet(34/39 Pages) CMLMICRO

34 / 39 page

Evaluation Kit for CMX868

EV8680

UM8680/2

Tx data is assumed to be clocked out of the BER Datatester on the rising edge of the Tx clock. This

data is sampled by the µC on the falling edge of the Tx clock.

The time tA varies as the clocks are adjusted to fit the exact byte periods of the evaluation devices.

Example BERT AT Command Setup

Ensure the BER Datatester is running (awaiting the external clocks supplied from the EV8680 boards)

and then start the Rx end board followed by the Tx end. The following sections show the required setup

for each end.

EV8680 Rx End Board Setup

1. Select V.22 communication standard (default is V.22 bis).

Command : ATB1<CR>

2. Enable/Disable Fixed Compromise and Auto Equalisers by writing to S-Register, S24.

3. Select the Operating Band and Enable/Disable the Descrambler by writing to S-Register S21.

4. Configure CMX868 Tx Gain by writing to S-Register, S25.

5. Configure CMX868 Rx Gain by writing to S-Register, S26.

6. Instruct the board to start the BERT routine as the Rx end.

Command : AT&F4<CR>

EV8680 Tx End Board Setup

1. Select V.22 communication standard (default is V.22 bis).

Command : ATB1<CR>

2. Enable/Disable Fixed Compromise Equaliser by writing to S-Register, S24.

3. Select the Operating Band and Enable/Disable the Scrambler by writing to S-Register S21.

4. Configure CMX868 Tx Gain by writing to S-Register, S25.

5. Configure CMX868 Rx Gain by writing to S-Register, S26.

6. Instruct the board to start the BERT routine as the Tx end.

Command : AT&F5<CR>

1.6.9

Trouble Shooting

Some terminal emulators have been found not to support full hardware flow control when transferring

text files. This could result in data loss when using this facility. If this problem is experienced users

should try using a different terminal emulator

To ensure successful negotiation and data transfer between the EV8680 and third party modems,

users should ensure their third party modem is configured to the correct protocol (see third party AT

command documentation).

EV8680 Datasheet(PDF) 34 Page - CML Microcircuits