TXC-06412BIOG Transwitch Corporation, TXC-06412BIOG Datasheet - Page 123

• Manufacturer Part Number: TXC-06412BIOG
• Manufacturer: Transwitch Corporation

Specifications of TXC-06412BIOG

• Lead Free Status / RoHS Status: Not Compliant

1 2 3 o f 2 26
Leak Immediate
11.5 RETIMER FIFO LEAK REGISTERS
Zone 4
11.4.1 Generation of Frame Reference Pulse
11.4.2 Locking on External Frame Reference Pulse
4
A System Frame Reference Pulse is generated every 125 us (8 kHz) when
ExtFramePulseExpected is deasserted. The generated System Frame Reference Pulse can
be monitored or used by other devices in order to align with the PHAST-12P via the
REFSYSFS lead.
When ExtFramePulseExpected is asserted, the PHAST-12P will lock on an external Frame
Reference Pulse (REFTXFS lead) and will generate a System Frame Reference Pulse. When
the distance between two consecutive Frame Reference Pulses is not exactly 125 us, a Loss
Of Frame defect (LOF) will be generated.
This LOF defect is cleared as soon as two consecutive pulses with a distance of 125 us have
been received. The System Frame Reference Pulse will still be generated during LOF state,
locked on previously accepted Frame Pulse.
Sampling of the Frame Reference Pulse is configurable on the positive or the negative
system clock edge (ExtFramePulseNegEdge).
Optionally an offset between the external Frame Reference Pulse and the internal System
Frame Reference Pulse can be provided (ExtFramePulseOffset).
The generated System Frame Reference Pulse can be monitored via the REFSYSFS lead.
The relationship between REFTXFS and REFSYSFS is represented in
All Retimers in PHAST-12P are able to reduce the number of pointer justifications to reduce
jitter on AU-3/AU-4/AU-4-Xc/STS-1/STS-3c/STS-6c/STS-9c/STS-12c pointers.
To provide this ability, the FIFO size is 29 words and the filling level of the FIFO is divided into
several zones, as depicted in
The center zone is called Dead Zone and is 5 words wide. In this zone, the FIFO is at half
filling and no pointer adjustments will be made.
- High Order Pointer Tracking, Retiming and Pointer Generation -
Leak Fast
Zone 3
4
Figure 36. Retimer FIFO Filling Levels
Leak Slow
Zone 2
4
Figure
Dead Zone
Zone 1
36.
FIFO center
5
Leak Slow
Zone 2
4
PRELIMINARY TXC-06412B-MB, Ed. 2
Leak Fast
Zone 3
4
PHAST-12P Device
Figure
Leak Immediate
13.
DATA SHEET
Zone 4
TXC-06412B
4
June 2005