Altera Stratix GX Transceiver - Manual (Page 55)

Altera Corporation 3–9
January 2005 Stratix GX Transceiver User Guide
Basic Mode
Figure 3–7. Example of How the Word Aligner Symbols Interact in Manual Bitslip Mode
8B/10B Decoder
The 8B/10B decoder is part of the Stratix GX transceiver block. The
8B/10B decoder restores the 8-bit data + 1-bit control identifier from the
10-bit code.
10-bit Decoding
The 8B/10B decoder translates the 10-bit encoded code into the 8-bit
equivalent data or control code. The 10-bit encoded code is received LSB
to MSB. The data received must come from the supported Dx.y or Kx.y
list. All 8B/10B control signals (Disparity error, control detect, and code
error) are pipelined with the data in the Stratix GX receiver block and are
edge-aligned with the data.
Figure 3–8 diagrams the 10-bit to 8-bit
conversion.
Table 3–2. Word Alignment Support for Basic Mode
Word Alignment Mode Effective Mode
Control
Signals
Status Signals
Manual 10-bit alignment
Mode Alignment to detected pattern when
allowed by the
rx_enacdet signal
rx_enacdet rx_syncstatus
rx_patterndetect
Manual 16-bit alignment
Mode Alignment to detected pattern when
allowed by the
rx_enacdet signal
rx_enacdet rx_syncstatus
rx_patterndetect
Manual bit-slipping
alignment mode Manual bit slip controlled by the device
logic array rx_bitslip rx_patterndetect
rx_recovclockout
rx_in
rx_word_align_out
rx_bitslip
rx_patterndetect
n n+1 n+2 n+3 n+4 n+5 n+6
11110000 01111000 00111100 00011110
11110000