S3042 AMCC (Applied Micro Circuits Corp), S3042 Datasheet - Page 24

• Manufacturer Part Number: S3042
• Description: Sonet/sdh/atm OC-48 1:8 Receiver
• Manufacturer: AMCC (Applied Micro Circuits Corp)

In some applications it is necessary to "forward clock" the data in a SONET/SDH system. In this application the
reference clock from which the high speed serial clock is synthesized and the parallel data clock both originate
from the same clock source. The timing control logic in the S3043 automatically generates an internal load signal
which has the fixed relationship to the reference clock. The logic takes into account the variation of the reference
clock to the internal load signal over temperature and voltage. The connections required to implement the design
are shown in the above figure. The setup and hold times for the PICLK to the data must be met by the customer
logic. For the timing diagram refer to Figure 16.
Possible Problems: In order to meet the jitter generation specifications required by SONET, the jitter of the
reference clock must be minimized. It may be difficult to meet the SONET jitter generation specifications using a
reference clock generated from the customer logic.
24
Figure 23.
S3043
CUSTOMER LOGIC
OSCILLATOR
16
SONET/SDH/ATM OC-48 16:1 TRANSMITTER
REFCLK P/N
PICLK P/N
PIN[15:0]
Pulse
DIV
FIFO
Read
PLL
S3043
August 10, 1999 / Revision E
APPLICATION NOTE