Intel® IXP42X product line and IXC1100 control plane processors—High-Speed Serial
Interfaces
Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
458 Order Number: 252480-006US
In Figure 86, the FBit to be transmitted is stored in the HSS Transmit FIFO. The HSS
knows which timeslot in the FIFO is holding the FBit, as it knows from the timeslot
counter and frame offset when the FBit should be transmitted.
In Figure 87, the FBit to be received is padded with 7 other bits (zeros) and placed into
the HSS Receive FIFO.
By using the IxHssAcc API, the following settings should be considered when
configuring HSS interface for T1 operation:
Frame size 193 bits (for T1).
Frame sync simultaneous with FBit - TX frame offset and RX frame offset should be
set due to HSS logic, different values due to external device can be accommodated.
Select use of input/output TX/RX frame syncs.
Select use of input/output clock, and clock speed.
Select negative/positive clock for generating/sampling frame in transmit/receive.
Select negative/positive clock for generating/sampling data in transmit/receive.
Figure 86. T1 Transmit Frame
hss_tx_data_out
hss_tx_clock
hss_tx_frame
FBit data1 data2 data 192data 191 FBit data1
Figure 87. T1 Receive Frame
hss_rx_datahss_rx_clockhss_rx_frameFBit data1 data 192data 191 FBitdata2 data1