HC4GX15 Datasheet, PDF (307/668 Pages) Altera Corporation – HardCopy IV Device Handbook

Chapter 1: HardCopy IV GX Transceiver Architecture
1–43
Transmitter Channel Datapath
Double-Width Mode
In double-width mode, the 8B/10B encoder operates in a cascaded mode, as shown in
Figure 1–29. The LSByte of the input data is encoded and transmitted prior to the
MSByte.
Figure 1–29. 8B/10B Encoder in Double-Width Mode
From the
Byte Serializer
8B/10B
Encoder
To the Serializer
datain[15:8]
control_code[1]
tx_forcedisp[1]
tx_dispval[1]
MSB Encoding
dataout[19:10]
datain[7:0]
control_code[0]
tx_forcedisp[0]
tx_dispval[0]
LSB Encoding
dataout[9:0]
© June 2009 Altera Corporation
HardCopy IV Device Handbook Volume 3