In SX Microcontrollers, SX/B Compiler and SX-Key Tool, XGen wrote:

Greetings all,

I would like to capture the basic rate isdn signal and send it via usb onto a PC.

Could someone have a look at the following and tell me if there are any glaring errors.

There are 4 wires, 2 for tx and 2 rx, the line speed is 144kbit/sec for Tx and the same for Rx. 
I would think the SX could handle 2 basic rate lines at the same time. Maybe more ?

So that would make it 576kbit/sec and 8 wires in total.
Im not sure how to get the line signal into 1's and 0's right now, as the line moves between +3v and -3v. I would have to have some analog circute to break it down into 4 wires with just 1's and 0's (0-5v) comming out of it. (any pointer here would be welcomed)

So here is my question:

How do i go about capturing the data without missing anything ?

a. Put the data through a Schmitt Trigger so that i dont get duplicate data.
	I suppose i can use this to turn the signal into 1's and 0's (0-5v)
b. Interrupt routine running at 144khz that reads the values from the 4 line.

In an Ideal world there should be minimal amount of jitter between the signals comming in, but can this cause me to lose data ?

Thanks for reading this far
X

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