HC4GX15 Datasheet, PDF (313/668 Pages) Altera Corporation – HardCopy IV Device Handbook

Chapter 1: HardCopy IV GX Transceiver Architecture
1–49
Transmitter Channel Datapath
Figure 1–36 shows the transmitter polarity inversion in double-width mode.
Figure 1–36. Transmitter Polarity Inversion in Double-Width Mode
Output from transmitter PCS
Converted data output to the
transmitter serializer
tx _invpolarity = high
0 ^MSB
1
1
1
0
0
0
1
0
0
1
0
0
0
1
1
1
0
1
1 _LSB
1 ^MSB
0
0
0
1
1
1
0
1
1
0
1
1
1
0
0
0
1
0
0 LSB
Transmitter Bit Reversal
By default, the HardCopy IV GX transmit bit order is LSBit to MSBit. In single-width
mode, the least significant bit of the 8- or 10-bit data word is transmitted first,
followed by the most significant bit. In double-width mode, the least significant bit of
the 16- or 20-bit data word is transmitted first, followed by the most significant bit.
The transmitter bit reversal feature allows reversing the transmit bit order as MSBit to
LSBit before it is forwarded to the serializer.
If you enable the transmitter bit reversal feature in Basic single-width mode, the 8-bit
D[7:0] or 10-bit D[9:0] data at the input of the serializer is rewired to D[0:7] or
D[0:9], respectively. If you enable the transmitter bit reversal feature in Basic
double-width mode, the 16-bit D[15:0] or 20-bit D[19:0] data at the input of the
serializer is rewired to D[0:15] or D[0:19], respectively.
© June 2009 Altera Corporation
HardCopy IV Device Handbook Volume 3