PMC-Sierra, Inc.

S/UNI-QUAD

DATASHEET

PM5349 S/UNI-QUAD

PMC-971239

ISSUE 6

SATURN USER NETWORK INTERFACE (155-QUAD)

 

 

 

13.5 Loopback Operation

The S/UNI-QUAD supports three loopback functions: line loopback, parallel diagnostic loopback and serial diagnostic loopback. Each channel's loopback modes operate independently. The loopback modes are activated by the PDLE, LLE and SDLE bits contained in the S/UNI-QUAD Channel Control Register.

The line loopback, see Figure 14, connects the high speed receive data and clock to the high speed transmit data and clock, and can be used for line side investigations (including clock recovery and clock synthesis). While in this mode, the entire receive path is operating normally and cells can be received through the FIFO interface.

The serial diagnostic loopback, see Figure 15, connects the high speed transmit data and clock to the high speed receive data and clock. While in this mode, the entire transmit path is operating normally and data is transmitted on the TXD+/- outputs.

The parallel diagnostic loopback, see Figure 16, connects the byte wide transmit data and clock to the byte wide receive data and clock. While in this mode, the entire transmit path is operating normally and data is transmitted on the TXD+/- outputs.

Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use

208

Page 214
Image 214
PMC-Sierra PM5349 manual Loopback Operation