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Generic High Speed Communication Block Interface

Block

Block

Mask

Mask

Description

The Generic High-Speed Communication Block is a link-layer protocol for high-speed serial communication. The block provides a user interface from which designer can develop a serial link.

The Generic High-Speed Communication Block uses Xilinx's Aurora 8B/10B Core in Framing as a medium for the high-speed communication link. 

Parameters

General Settings

Channel SelectionSelects the current Communication Channel number.
MGT Reference Selection

Selects the reference clock speed of the Multi-Gigabit Transceiver (MGT) of the communication Channel Link. It is forbidden to have different reference clocks in the same MGT Quad.

  • Quad 119 = Channels 0 to 3
  • Quad 118 = Channels 4 to 7
  • Quad 117 = Channels 8 to 11
  • Quad 116 = Channels 12 to 15
Line Rate Selection

Selects the line rate of the communication channel. It is forbidden to have different line rate in the same MGT Quad.

  • Quad 119 = Channel 0 to 3
  • Quad 118 = Channel 4 to 7
  • Quad 117 = Channel 8 to 11
  • Quad 116 = Channel 12 to 15. 
Provide RX FIFO Overflow portProvides the FIFO overflow status port.
Provide Status portsProvides the Aurora communication core status ports.
Provide RX Last Data PortWhen checked, an RX Last Data output port is made visible to the user. This port signals the occurrence of the last data of a frame when high.
Provide Statistics portsProvide the Aurora communication core status ports.
Provide GT_RESET portProvide a reset port to reset the internal MGT in the Aurora Core.
Ignore CRC Check (RX)Cyclic Redundancy Check error is ignored/disregarded when this parameter is enabled.

Advanced Settings

Optimal values are already configured by default.

MGT 'TXDIFFCTRL' parameterThis parameter sets the Driver Swing Control value of the MGT  in order to maximize signal integrity. 
MGT 'TXPRECURSOR' parameterThese parameters set the MGT pre-cursor TX pre-emphasis. 
MGT 'TXPOSTCURSOR' parameter

Inputs

TX_DATAVALIDWhen high indicates that the data present on port TX_DATA is valid when TX_READY is also high.
TX_DATAHolds a 32-bit outgoing data.
TX_LASTDATAIndicates the last data in the protocol frame. Signals the end of a frame (Active High).

Optional Ports

This port is available only when Provide GT_RESET Port option is checked.

GT_RESETAllows the capability to reset the internal MGT of the Aurora Core.

Outputs

TX_READYIndicates the communication block is ready to accept incoming data. The block accepts data when both TX_DATAVALID and TX_READY are asserted high.
RX_DATAVALIDIndicates that the data present on port RX_DATA is valid.
RX_DATAHolds the incoming data from the channel partner.
FC_CRC_ERRORAurora status port indicating a CRC error has been detected.

Optional Ports

This port is available only when Provide RX FIFO Overflow option is checked.

FC_FIFO_OVERFLOW_ERRORAurora status port indicating the communication interface detects a FIFO Overflow occurrence.

These ports are available only when Provide Status Ports option is checked.

HARD_ERRORAurora Status port indicating that the Aurora core has detected a hard error. The core monitors each MGT for hardware errors such as buffer overflow/underflow and loss of lock.
SOFT_ERRORAurora Status port indicating a Soft error has been detected in the incoming serial stream.
FRAME_ERRORAurora Status port indicating a Frame Error. Frames with no data, consecutive Start of Frame symbols, and consecutive End of Frame symbols are considered as Frame Error.
LANE_UPAurora Status port indicating a successful lane initialization.
CHANNEL_UPAurora Status port indicating a successful channel initialization and the channel is ready to send/receive data.

These ports are available only when Provide Statistic Ports option is checked.

NbrRcvDataPerFrameNumber of data received in a frame.
TimeBetweenFrameElapsed time between successive frames.
NbrOfFrameErrorNumber of Frame Error since the start of the simulation.
nbrRcvFrameNumber of frame received since the beginning of the simulation.

Block Handshaking

Transmitting Data

The Generic High SPeed Communication Block is a synchronous interface. The Block samples the data on the interface only on the positive edge of USER_CLK, and only on the cycles when both TX_DATAVALID and TX_READY are asserted (High).

Typical Transaction on the transmit interface:

Typical Transaction on the transmit interface

When the signals are sampled, they are only considered valid if MS_VALID is asserted. The user application can deassert MS_VALID on any clock cycle; this causes the MMC Converter core to ignore the input data for that cycle. If this occurs in the middle of a frame, idle symbols are sent through the Aurora 8B/10B channel, which eventually result in a idle cycles during the frame when it is received at the RX user interface.

Typical Transaction on the transmit interface with throttling

Typical Transaction on the transmit interface with throttling

To end the data transfer, the user asserts TX_LASTDATA. The transaction ends when TX_LASTDATA, TX_DATAVALID and TX_READY are all asserted high.

Receiving Data

The Generic High Speed Communication block asserts the signal RX_DATAVALID when the incoming data presents on RX_DATA bus is valid on the user interface. Applications should ignore any values on the receiving ports sampled while the valid flags (RX_DATAVALID) are deasserted (Low).



Note: The Generic High Speed Communication block has a CRC checker mecanism to verify the validity of the data stream. Consequently, there is a latency of 1 frame since the block needs to receive the complete frame and verify the CRC before putting all the data on its output ports.



Characteristics and Limitations

This Block has no specific characteristics or limitations

Direct FeedthroughN/A
Discrete sample timeN/A
XHP supportN/A
Work offlineYES

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