DS2141A Creating a DS/ESF Chan

Notes:

1. This application uses "looped" timing (i.e., RCLK is tied to TCLK)
2. MHz clock source is used as a transmit clock if no signal exists on the receive side; if the DS2291 declares a carrier loss, then the source of the TCLK will be switched from the recovered clock to the locally accurate 1.544 MHz source.
3. The DS2141A will be used to detect the normal loop codes and to decode and encode the Facility Data Link (upon request, transportable C code firmware is available from Dallas Semiconductor that implements both ANSI T1.403 and AT&T TR54016).