CT2579 datasheet(20/41 Pages) AEROFLEX

20 / 41 page

APPLICATION NOTE #108

Released 9/98

b) The self test data word is read from the appropriate RAM location, transferred to the encoder

and transmitted contiguously following the command word.

c) The Command word is received by the Manchester decoder, if valid and with correct RT

address or broadcast is stored in the RT protocol.

d) The data word is received by the decoder and if valid is stored in the 32 word data memory.

e) The RT protocol will validate the message and if successful will write the Command word to

the 32 word Command / Status memory and transfer the data word to the appropriate RAM

location.

As the data word received is written to the same RAM location that it was originally accessed

from, the contents should be altered while the self test is in progress (eg. write 0000). This can be

done immediately after the BC to RT transfer was initiated. There is approx 45 us for the self test

to complete.

6. To ensure that the RAM contents have been altered it is advisable to read the data back from the

RAM.

7. On completion of a successful self test the signal NCMDSTRB will go active low, after which the

data can be read from the RAM and compared with the data used in the self test.

8. In addition the Command word used in the self test may be read from 0 00 00.

9. Disable self test by writing to 1 00 08. The device will revert back to its original state (BC or RT).

CT2579 Folha de dados(PDF) 20 Page - Aeroflex Circuit Technology