Altera Corporation
2–103
October 2007
Stratix II GX Device Handbook, Volume 2
Stratix II GX Transceiver Architecture Overview
Figure 2–78. Deletion of Skip Characters in Double-Width Mode
The rate matcher inserts skip characters by pairs on the upper and lower
byte (
Figure 2–79
). The insertion occurs after a /K28.5/ or the
programmed control code group is detected by the rate matcher. If the
comma is detected on the lower byte, the high byte must be a skip
character. The insertion happens on the next double byte, if needed. If the
comma appears on the upper byte, and the skip character is in the next
lower byte, the insertion occurs on the double byte after the comma
character, if needed.
Figure 2–79. Insertion of Skip Characters in Double-Width Mode
8B/10B Decoder
The 8B/10B decoder (
Figure 2–80
) is part of the Stratix II GX transceiver
digital blocks and lies in the receiver path between the rate matcher and
the byte deserializer blocks. The 8B/10B decoder operates in two modes:
single-width and double-width modes and can be bypassed if 8B/10B
decoding is not needed. In single-width mode, the 8B/10B decoder
K28.0
K28.0
Dx.y
Dx.y
Dx.y
datain[15..8]
clock
K28.5
K28.0
Dx.y
Dx.y
Dx.y
datain[7..0]
K28.0
Dx.y
Dx.y
Dx.y
Dx.y
dataout[15..8]
K28.5
Dx.y
Dx.y
Dx.y
Dx.y
dataout[7..0]
Two Skips Deleted
K28.5
Dx.y
Dx.y
Dx.y
Dx.y
datain[15..8]
clock
Dx.y
Dx.y
Dx.y
Dx.y
datain[7..0]
K28.5
K28.0
Dx.y
Dx.y
Dx.y
dataout[15..8]
Dx.y
K28.0
Dx.y
Dx.y
dataout[7..0]
Two Skips Inserted
K28.0
K28.0