Rainbow Electronics DS21458 - Manual (Page 20)

DS21455/DS21458 Quad T1/E1/J1 Transceivers
20 of 270
5. PIN FUNCTION DESCRIPTION
5.1 Transmit Side Pins
Signal Name:
TCLK
Signal Description: Transmit Clock
Signal Type: Input
A 1.544 MHz or a 2.048MHz primary clock. Used to clock data through the transmit-side formatter.
Signal Name:
TSER
Signal Description: Transmit Serial Data
Signal Type: Input
Transmit NRZ serial data. Sampled on the falling edge of TCLK when the transmit-side elastic store is disabled. Sampled on
the falling edge of TSYSCLK when the transmit-side elastic store is enabled.
Signal Name:
TCHCLK
Signal Description: Transmit Channel Clock
Signal Type: Output
A 192kHz (T1) or 256kHz (E1) clock that pulses high during the LSB of each channel. Can also be programmed to output a
gated transmit-bit clock for fractional T1/E1 applications. Synchronous with TCLK when the transmit-side elastic store is
disabled. Synchronous with TSYSCLK when the transmit-side elastic store is enabled. Useful for parallel-to-serial conversion
of channel data.
Signal Name:
TCHBLK
Signal Description: Transmit Channel Block
Signal Type: Output
A user-programmable output that can be forced high or low during any of the channels. Synchronous with TCLK when the
transmit-side elastic store is disabled. Synchronous with TSYSCLK when the transmit-side elastic store is enabled. Useful for
locating individual channels in drop-and-insert applications, for external per-channel loopback, and for per-channel
conditioning.
Signal Name:
TSYSCLK
Signal Description: Transmit System Clock
Signal Type: Input
1.544MHz, 2.048MHz, 4.096MHz, 8.192MHz, or 16.384MHz clock. Only used when the transmit-side elastic-store function
is enabled. Should be tied low in applications that do not use the transmit-side elastic store. See the Interleaved PCM Bus
Operation section for details on 4.096MHz, 8.192MHz, and 16.384MHz operation using the IBO.
Signal Name:
TLCLK
Signal Description: Transmit Link Clock
Signal Type: Output
Demand clock for the transmit link data [TLINK] input.
T1 Mode: A 4kHz or 2kHz (ZBTSI) clock.
E1 Mode: A 4kHz to 20kHz clock.
Signal Name:
TLINK
Signal Description: Transmit Link Data
Signal Type: Input
If enabled, this pin will be sampled on the falling edge of TCLK for data insertion into either the FDL stream (ESF) or the Fs-
bit position (D4) or the Z-bit position (ZBTSI) or any combination of the Sa bit positions (E1).