HC4GX15 Datasheet, PDF (375/668 Pages) Altera Corporation – HardCopy IV Device Handbook

Chapter 1: HardCopy IV GX Transceiver Architecture
Receiver Channel Datapath
1–111
Figure 1–96. MSByte and LSByte of the Four-Bit Transmitter Data Straddled Across Two Word Boundaries
Transmitter
Receiver
tx_datain[31:16]
(MSBytes) ^{D3D4 D7D8}
tx_datain[15:0]
(LSBytes)
D1D2
D5D6
Byte
Serializer
xx D1D2 D2D4 D5D6 D7D8 xx
Byte
Deserializer
D1D2
xx
D5D6
D3D4
rx_dataout[31:16]
xx
(MSBytes)
rx_dataout[15:0]
D7D8 _(LSBytes)
HardCopy IV GX transceivers have an optional byte ordering block in the receiver
datapath that you can use to restore proper byte ordering before forwarding the data
to the core fabric. The byte ordering block looks for the user-programmed byte
ordering pattern in the byte-deserialized data. You must select a byte ordering pattern
that you know appears at the LSByte(s) position of the parallel transmitter data. If the
byte ordering block finds the programmed byte ordering pattern in the MSByte(s)
position of the byte-deserialized data, it inserts the appropriate number of
user-programmed PAD bytes to push the byte ordering pattern to the LSByte(s)
position, thereby restoring proper byte ordering.
Byte Ordering Block in Single-Width Modes
The byte ordering block is available in the following single-width functional modes:
■ SONET/SDH OC-48
■ Basic single-width mode with:
■ 16-bit core fabric-transceiver interface
■ No 8B/10B decoder (8-bit PMA-PCS interface)
■ Word aligner in manual alignment mode
■ Basic single-width mode with:
■ 16-bit core fabric-transceiver interface
■ 8B/10B decoder
■ Word aligner in automatic synchronization state machine mode
1 For more information about configurations that allow the byte ordering block in the
receiver datapath, refer to “Basic Single-Width Mode Configurations” on page 1–120.
The Quartus II software automatically configures the byte ordering pattern and byte
ordering PAD pattern for SONET/SDH OC-48 functional mode. For more
information, refer to “OC-48 Byte Ordering” on page 1–173.
In Basic single-width mode, you can program a custom byte ordering pattern and
byte ordering PAD pattern in the ALTGX MegaWizard Plug-In Manager. Table 1–26
shows the byte ordering pattern length allowed in Basic single-width mode.
© June 2009 Altera Corporation
HardCopy IV Device Handbook Volume 3