PMC-Sierra, Inc.
TELECOM STANDARD PRODUCT
PMC-930917
ISSUE 1
PM6541 E1XC-EVBD
E1XC EVALUATION DAUGHTERBOARD
2.7
E1XC Devices
Up to two E1XC devices can be placed on the daughterboard at a time. Each
device runs independent of the other, except when explicit connections are made
through the header strips (i.e. when configured as a jitter attenuating format
converter). All internal registers are individually accessible and each device has
been set up with individual receiver, transmitter and backplane access through
headers and connectors. A full description of the E1XC device is beyond the scope
of this document. For more information, refer to the PM6341 E1XC datasheet.
2.8
"CSU" Connection Blocks
While the main purpose of the evaluation daughterboard is to provide unrestricted
access to all of the features of the E1XC device, one application is conveniently
provided which allows easy evaluation of most of the features of the device. By
plugging in shorting jumpers into the two 16 pin CSU DIP sockets (U5 and U6) on
the daughterboard, the two E1XCs are connected back to back to implement a jitter-
attenuating format converter (a function often implemented within a CSU) as
described in the E1XC datasheet. These CSU DIP socket jumpers make almost all
of the necessary connections except for the signals BRCLK, BRFPI, and BTCLK.
Connections for these signals are made through E-W and W-E jumper blocks J19,
J20, J21, J22, J23, and J24. By installing jumper connections between pin 1 and
pin 2 of jumper blocks J19 and J20, between pin 3 and pin 4 of each of jumper
blocks J21, J22, J23, J24, and between pin 2 and 3 of jumper block J30, a "CSU"
like application can be implemented where the 2.048 MHz clock for the backplane
between the two E1XC devices is provided by the MT8940, which in turn is locked to
the recovered clock provided by E1XC #1. Variations of this application can be
explored by using the other options provided on the jumper blocks. Connections are
provided for 2.048 MHz and externally supplied backplane clock rates.
4
PMC [ PMC-SIERRA, INC ]
