PM4354-PI datasheet(48/463 Pages) PMC

48 / 463 page

RELEASED

PM4354 COMET-QUAD

DATASHEET

PMC-1990315

ISSUE 6

FOUR CHANNEL COMBINED E1/T1/J1

TRANSCEIVER / FRAMER

PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC. AND FOR ITS CUSTOMERS’ INTERNAL USE

FUNCTIONAL DESCRIPTION

9.1

Quadrants

The COMET-QUAD’s four E1/T1 transceivers/framers operate independently and can be

configured to operate uniquely. The COMET-QUAD transceiver/framers (or quadrants) do share a

common XCLK crystal clock input and internal clock synthesizer; hence a single CSU

Configuration register is present and all quadrants share a common E1/T1B mode register bit.

When an H-MVIP interface is enabled, the interface interacts with all four quadrants, and hence

some common settings are required.

9.2

Receive Interface

The analog receive interface is configurable to operate in both E1 and T1 short-haul and long-haul

applications. Short-haul T1 is defined as transmission over less than 655 ft of cable. Short-haul

E1 is defined as transmission on any cable that attenuates the signal by less than 6 dB.

For long-haul signals, unequalized long- or short-haul bipolar alternate mark inversion (AMI)

signals are received as the differential voltage between the RXTIP and RXRING inputs. The

COMET-QUAD typically accepts unequalized signals that are attenuated for both T1 and E1

signals and are non-linearly distorted by typical cables.

For short-haul, the slicing threshold is set to a fraction of the input signal’s peak amplitude, and

adapts to changes in this amplitude. The slicing threshold is programmable, but is typically 67%

and 50% for DSX-1 and E1 applications, respectively. Abnormally low input signals are detected

when the input level is below a programmable threshold, which is typically 140 mV for E1 and

105 mV for T1.

PM4354-PI bảng dữ liệu(PDF) 48 Page - PMC-Sierra, Inc