EV6240 Datasheet, PDF (35/47 Pages) CML Microcircuits – Opto-Isolated serial interface capability

Evaluation Kit for CMX624/CMX644A
EV6240
State 3
When Rx Energy flag is clear start 60ms Silence Timer
If Validation Timer expires the 2100Hz Answer tone has been present for too long so Hang Up and
Exit.
State 4
Set up CMX624 to detect High Band FSK.
Wait until the Rx Energy flag is set then goto State 4b.
If the Wait for Carrier after Dial Timer expires before the Rx Energy flag is set then Hang Up and Exit.
State 4b
Check Communications Standard selected by user (Bell or ITU-T).
If Bell
Goto State 4c.
Else
If 60ms Silence Timer has not expired Hang Up and Exit.
State 4c
Restart Validation Timer (setting stored in S18).
Whilst the Rx Energy flag (currently detecting High Band FSK) is set the Rx data is monitored to
ensure 95% of 1’s (marks) are detected for 160ms.
If 95% of High Band FSK 1’s are detected for 160ms
Turn on Modem CD LED.
Start a 450ms Timer
Goto State 5.
If Validation Timer expires before 95% of High Band FSK 1’s detected then Hang Up and Exit.
State 5
Wait until 450ms Timer expires then set up the CMX624 to Tx Low Band FSK 1’s.
Start a 320ms Timer
State 6
Wait until 320ms Timer expires then goto Data Transfer Mode.
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© 1999 Consumer Microcircuits Limited
UM6240/3