Subversion Repositories rio

--

-- clk - System clock.

-- areset_n - System reset. Asynchronous, active low. 

--

-- portLinkTimeout_i - The number of ticks to wait for a packet-accepted before

--   a timeout occurrs.

-- linkInitialized_o - Indicates if a link partner is answering with valid

--   status-control-symbols. 

-- inputPortEnable_i - Activate the input port for non-maintenance packets. If

--   deasserted, only non-maintenance packets are allowed.

-- outputPortEnable_i - Activate the output port for non-maintenance packets.

--   If deasserted, only non-maintenance packets are allowed.

--

-- This interface makes it possible to read and write ackId in both outbound

-- and inbound directions. All input signals are validated by localAckIdWrite.

-- localAckIdWrite_i - Indicate if a localAckId write operation is ongoing.

--   Usually this signal is high one tick. 

-- clrOutstandingAckId_i - Clear outstanding ackId, i.e. reset the transmission

--   window. The signal is only read if localAckIdWrite_i is high.

-- inboundAckId_i - The value to set the inbound ackId (the ackId that the

--  next inbound packet should have) to. This signal is only read if localAckIdWrite

--  is high.

-- outstandingAckId_i - The value to set the outstanding ackId (the ackId

--   transmitted but not acknowledged) to. This signal is only read if localAckIdWrite

--   is high.

-- outboundAckId_i - The value to set the outbound ackId (the ackId that the

--   next outbound packet will have) to. This signal is only read if localAckIdWrite

--   is high.

-- inboundAckId_o - The current inbound ackId.

-- outstandingAckId_o - The current outstanding ackId.

-- outboundAckId_o - The current outbound ackId.

--

-- This is the interface to the packet buffering sublayer. 

-- The window signals are used to send packets without removing them from the

-- memory storage. This way, many packet can be sent without awaiting

-- packet-accepted symbols and if a packet-accepted gets lost, it is possible

-- to revert and resend a packet. This is achived by reading readWindowEmpty

-- for new packet and asserting readWindowNext when a packet has been sent.

-- When the packet-accepted is received, readFrame should be asserted to remove the

-- packet from the storage. If a packet-accepted is missing, readWindowReset is

-- asserted to set the current packet to read to the one that has not received

-- a packet-accepted.

-- readFrameEmpty_i - Indicate if a packet is ready in the outbound direction.

--   Once deasserted, it is possible to read the packet content using

--   readContent_o to update readContentData and readContentEnd.

-- readFrame_o - Assert this signal for one tick to discard the oldest packet.

--   It should be used when a packet has been fully read, a linkpartner has

--   accepted it and the resources occupied by it should be returned to be

--   used for new packets.

-- readFrameRestart_o - Assert this signal to restart the reading of the

--   current packet. readContentData and readContentEnd will be reset to the

--   first content of the packet. 

-- readFrameAborted_i - This signal is asserted if the current packet was

--   aborted while it was written. It is used when a transmitter starts to send a

--   packet before it has been fully received and it is cancelled before it is

--   completed. A one tick asserted readFrameRestart signal resets this signal.

-- readWindowEmpty_i - Indicate if there are more packets to send.

-- readWindowReset_o - Reset the current packet to the oldest stored in the memory.

-- readWindowNext_o - Indicate that a new packet should be read. Must only be

--   asserted if readWindowEmpty is deasserted. It should be high for one tick.

-- readContentEmpty_i - Indicate if there are any packet content to be read.

--   This signal is updated directly when packet content is written making it

--   possible to read packet content before the full packet has been written to

--   the memory storage.

-- readContent_o - Update readContentData and readContentEnd.

-- readContentEnd_i - Indicate if the end of the current packet has been

--   reached. When asserted, readContentData is not valid.

-- readContentData_i - The content of the current packet.

-- writeFrameFull_i - Indicate if the inbound packet storage is ready to accept

--   a new packet.

-- writeFrame_o - Indicate that a new complete inbound packet has been written.

-- writeFrameAbort_o - Indicate that the current packet is aborted and that all

--   data written for this packet should be discarded. 

-- writeContent_o - Indicate that writeContentData is valid and should be

--   written into the packet content storage. 

-- writeContentData_o - The content to write to the packet content storage.

--

-- This is the interface to the PCS (Physical Control Sublayer). Four types of

-- symbols exist, idle, control, data and error.

-- Idle symbols are transmitted when nothing else can be transmitted. They are

-- mainly intended to enforce a timing on the transmitted symbols. This is

-- needed to be able to guarantee that a status-control-symbol is transmitted

-- at least once every 256 symbol.

-- Control symbols contain control-symbols as described by the standard.

-- Data symbols contains a 32-bit fragment of a RapidIO packet.

-- Error symbols indicate that a corrupted symbol was received. This could be

-- used by a PCS layer to indicate that a transmission error was detected and

-- that the above layers should send link-requests to ensure the synchronism

-- between the link-partners.

-- The signals in this interface are:

-- portInitialized_i - An asserted signal on this pin indicates that the PCS

--   layer has established synchronization with the link and is ready to accept

--   symbols. 

-- outboundSymbolEmpty_o - An asserted signal indicates that there are no

--   outbound symbols to read. Once deasserted, outboundSymbol_o will be

--   already be valid. This signal will be updated one tick after

--   outboundSymbolRead_i has been asserted.

-- outboundSymbolRead_i - Indicate that outboundSymbol_o has been read and a

--   new value could be accepted. It should be active for one tick. 

-- outboundSymbol_o - The outbound symbol. The two MSB bits are the type of the

--   symbol.

--   bit 34-33 

--   00=IDLE, the rest of the bits are not used.

--   01=CONTROL, the control symbols payload (24 bits) are placed in the MSB

--     part of the symbol data.

--   10=ERROR, the rest of the bits are not used.

--   11=DATA, all the remaining bits contain the data-symbol payload.

-- inboundSymbolFull_o - An asserted signal indicates that no more inbound

--   symbols can be accepted.

-- inboundSymbolWrite_i - Indicate that inboundSymbol_i contains valid

-- information that should be forwarded. Should be active for one tick.

-- inboundSymbol_i - The inbound symbol. See outboundSymbol_o for formating.