Evaluation Kit User Manual for FX828 and FX829

EV8000

© 2004 CML Microsystems Plc

27

UM8000/4

1.6.3.22 FFSK Rx Message

Select FFSKRX and AMP1 by clicking on their respective checkboxes in the Control 1 write

register and enable the required synchronisation bit in the Control 3 / IRQ Enable write register. If

RX SYNC WORD PRIME is selected, enter a 2-byte RX SYNC word in hex, before clicking on the

Update button. If required, other control bits can be set before the Update button is clicked i.e.

baud rate, etc.

The user can now setup the FFSK Rx Message section of the device form. Start by entering the

number of data bytes in a single message, click on the Rx Bytes edit box and enter an integer

number(1-11).

If a FFSK Rx checksum is required based on the number of bytes expected, the Rx checksum

should be set by checking this checkbox. The FFSK Rx message setup can be stored in memory

at any stage by clicking on the Update button. To transfer the data to the

µC board and thus start

receiving FFSK messages the user should click on the Rx Message Start button. The FFSK

message received will be displayed in the read-only, multiline, vertically scrolled edit box. This

edit box will clear automatically when a maximum number of lines is reached (500) . However a

clear button is provided to allow the user to clear the edit box at any stage.

Up to 15 following words can be received by the FFSK Rx Message section, by clicking on the

appropriate edit box and entering the required number. A following word comprises of message

data bytes and checksum (if transmitted) immediately following the previous message without

further synchronisation.

Whilst receiving FFSK messages the FFSK Rx Message Start button is disabled until the FFSK

Rx Stop button is clicked by the user.

Rx message display format with Rx checksum:

Message Synchronisation Codeword, D(message data bytes), C(2-byte checksum, validity)

i.e. SYNC, D(AA,11,33), C(85,2A, TRUE)

Rx message display format without Rx checksum:

Message Synchronisation Codeword, D(message data bytes)

i.e. WORD, D(AA,11,33)

The Rx Message Synchronisation Codeword will be either SYNT, SYNC or WORD.

Note:

The FX829 device form cannot receive continuous FFSK messages when the inter-message

delay is <100ms.