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RocketIO™ Transceiver User Guide
25
UG024 (v3.0) February 22, 2007
List of Available Ports
R
REFCLK
I
1
High-quality reference clock driving transmission (reading TX FIFO,
and multiplied for parallel/serial conversion) and clock recovery.
REFCLK frequency is accurate to ±100 ppm. When running an
asynchronous system, this accuracy must be met by both reference
clocks. This clock originates off the device, is routed through fabric
interconnect, and is selected by REFCLKSEL.
REFCLK2
I
1
An alternative to REFCLK. Can be selected by REFCLKSEL.
REFCLKSEL
I
1
Selects the reference clock to use:
Low = selects REFCLK if REF_CLK_V_SEL = 0
selects BREFCLK if REF_CLK_V_SEL = 1
High = selects REFCLK2 if REF_CLK_V_SEL = 0
selects BREFCLK2 if REF_CLK_V_SEL = 1
See
.
RXBUFSTATUS
O
2
Receiver elastic buffer status. Bit 1 indicates if an overflow/underflow
error has occurred when asserted High. Bit 0 indicates that the buffer is
at least half-full when asserted High.
RXCHARISCOMMA
(3)
O
1, 2, 4
Similar to RXCHARISK except that the data is a comma.
RXCHARISK
(3)
O
1, 2, 4
If 8B/10B decoding is enabled, it indicates that the received data is a
K-character when asserted High. Included in Byte-mapping. If 8B/10B
decoding is bypassed, it remains as the first bit received (Bit “a”) of the
10-bit encoded data (see
).
RXCHECKINGCRC
O
1
CRC status for the receiver. Asserts High to indicate that the receiver
has recognized the end of a data packet. Only meaningful if
RX_CRC_USE = TRUE.
RXCLKCORCNT
O
3
Status that denotes occurrence of clock correction or channel bonding.
This status is synchronized on the incoming RXDATA. See
RXCOMMADET
O
1
Signals that a comma has been detected in the data stream.
To assure signal is reliably brought out to the fabric for different data
paths, this signal may remain High for more than one
USRCLK/USRCLK2 cycle.
RXCRCERR
O
1
Indicates if the CRC code is incorrect when asserted High. Only
meaningful if RX_CRC_USE = TRUE.
RXDATA
(3)
O
8, 16, 32 Up to four bytes of decoded (8B/10B encoding) or encoded (8B/10B
bypassed) receive data.
RXDISPERR
(3)
O
1, 2, 4
If 8B/10B encoding is enabled it indicates whether a disparity error has
occurred on the serial line. Included in Byte-mapping scheme.
Table 1-5:
GT_CUSTOM
(1)
, GT_AURORA, GT_FIBRE_CHAN
(2)
, GT_ETHERNET
(2)
,
GT_INFINIBAND, and GT_XAUI Primitive Ports
(Continued)
Port
I/O
Port
Size
Definition
Product Not Recommended for New Designs