Rxcharisk And Rxrundisp; Rxdisperr; Rxnotintable; Table 2-7: 8B/10B Bypassed Signal Significance - Xilinx RocketIO X User Manual

Block Level Functions

Table 2-7: 8B/10B Bypassed Signal Significance

Signal
RXCHARISK
RXRUNDISP

RXDISPERR

RXCHARISK and RXRUNDISP

RXCHARISK and RXRUNDISP are dual-purpose ports for the receiver depending
whether 8B/10B decoding is enabled.
decoding is enabled, these ports function as byte-mapped status ports of the received
data.
In the encoding configuration, when RXCHARISK is asserted that byte of the received data
is a control (K) character. Otherwise, the received byte of data is a data character. (See
Appendix B, "8B/10B Valid
the received byte is either negative or positive. RXRUNDISP is asserted to indicate positive
disparity. This is used in cases like the
In the bypassed configuration, RXCHARISK and RXRUNDISP are additional data bits for
the 10-,
20-, 40-, or 80-bit buses. This is similar to the transmit side. RXCHARISK[0:7] relates to bits
9, 19, 29, 39, 49, 59, 69, and 79 while RXRUNDISP pertains to bits 8, 18, 28, 38, 48, 58, 68, and
78 of the data bus. See
RXDISPERR
RXDISPERR is a status port for the receiver that is byte-mapped to the RXDATA. When a
bit is asserted, a disparity error occurred on the received data. This usually indicated that
the data is corrupt by bit errors, transmission of an invalid control character, or for cases
when normal disparity is not required such as in the

RXNOTINTABLE

RXNOTINTABLE is asserted whenever the received data is not in the 8B/10B tables. The
data received on bytes marked by RXNOTINTABLE are invalid. This port is also byte-
mapped to RXDATA and is only used when the 8B/10B decoder is enabled.
RocketIO™ X Transceiver User Guide
UG035 (v1.5) November 22, 2004
Received byte is a K-character
0 Indicates running disparity is
NEGATIVE
1 Indicates running disparity is
POSITIVE
Disparity error occurred on current byte Unused
Figure
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Function
Part of 10-bit encoded byte
(see
RXCHARISK[0],
(or: [1] / [2] / [3] /[4]/[5]/[6]/[7])
RXRUNDISP[0],
(or: [1] / [2] / [3] /[4]/[5]/[6]/[7])
RXDATA[7:0]
(or: [15:8] / [23:16] / [31:24]/
[39:32]/[47:40]/[55:48]/[63:56})
Figure 2-8 shows this dual functionality. When
Characters"). The RXRUNDISP port indicates the disparity of
"Vitesse Disparity Example," page
2-8.
"Vitesse Disparity Example," page
Figure 2-6):
52.
R
52.
51