Entity: Pgp2bTxSched
- File: Pgp2bTxSched.vhd
Diagram
Description
Title : PGPv2b: https://confluence.slac.stanford.edu/x/q86fD
Company : SLAC National Accelerator Laboratory
Description:
Transmit scheduler interface module for the Pretty Good Protocol core.
This file is part of 'SLAC Firmware Standard Library'. It is subject to the license terms in the LICENSE.txt file found in the top-level directory of this distribution and at: https://confluence.slac.stanford.edu/display/ppareg/LICENSE.html. No part of 'SLAC Firmware Standard Library', including this file, may be copied, modified, propagated, or distributed except according to
the terms contained in the LICENSE.txt file.
Generics
| Generic name | Type | Value | Description |
|---|---|---|---|
| TPD_G | time | 1 ns | |
| VC_INTERLEAVE_G | integer | 1 | Interleave Frames |
| NUM_VC_EN_G | integer range 1 to 4 | 4 |
Ports
| Port name | Direction | Type | Description |
|---|---|---|---|
| pgpTxClkEn | in | sl | Master clock Enable |
| pgpTxClk | in | sl | Master clock |
| pgpTxClkRst | in | sl | Synchronous reset input |
| pgpTxFlush | in | sl | Flush the link |
| pgpTxLinkReady | in | sl | Local side has link |
| schTxSOF | in | sl | Cell contained SOF |
| schTxEOF | in | sl | Cell contained EOF |
| schTxIdle | out | sl | Force IDLE transmit |
| schTxReq | out | sl | Cell transmit request |
| schTxAck | in | sl | Cell transmit acknowledge |
| schTxTimeout | out | sl | Cell transmit timeout |
| schTxDataVc | out | slv(1 downto 0) | Cell transmit virtual channel |
| vc0FrameTxValid | in | sl | User frame data is valid |
| vc1FrameTxValid | in | sl | User frame data is valid |
| vc2FrameTxValid | in | sl | User frame data is valid |
| vc3FrameTxValid | in | sl | User frame data is valid |
| vc0RemAlmostFull | in | sl | Remote flow control |
| vc1RemAlmostFull | in | sl | Remote flow control |
| vc2RemAlmostFull | in | sl | Remote flow control |
| vc3RemAlmostFull | in | sl | Remote flow control |
Signals
| Name | Type | Description |
|---|---|---|
| currValid | sl | |
| currVc | slv(1 downto 0) | |
| nextVc | slv(1 downto 0) | |
| arbVc | slv(1 downto 0) | |
| arbValid | sl | |
| vcInFrame | slv(3 downto 0) | |
| intTxReq | sl | |
| intTxIdle | sl | |
| nxtTxReq | sl | |
| nxtTxIdle | sl | |
| nxtTxTimeout | sl | |
| intTxTimeout | sl | |
| vcTimerA | slv(23 downto 0) | |
| vcTimerB | slv(23 downto 0) | |
| vcTimerC | slv(23 downto 0) | |
| vcTimerD | slv(23 downto 0) | |
| vcTimeout | slv(3 downto 0) | |
| gateTxValid | slv(3 downto 0) | |
| curState | slv(2 downto 0) | |
| nxtState | slv(2 downto 0) |
Constants
| Name | Type | Value | Description |
|---|---|---|---|
| ST_RST_C | slv(2 downto 0) | "001" | Schedular state |
| ST_ARB_C | slv(2 downto 0) | "010" | |
| ST_CELL_C | slv(2 downto 0) | "011" | |
| ST_GAP_A_C | slv(2 downto 0) | "100" | |
| ST_GAP_B_C | slv(2 downto 0) | "101" | |
| ST_GAP_C_C | slv(2 downto 0) | "110" |
Processes
- unnamed: ( pgpTxClk )
Description
State transition logic
- unnamed: ( curState, arbValid, arbVc, currVc, schTxAck, vcInFrame, currValid, vcTimeout )
Description
Scheduler state machine
- unnamed: ( currVc, gateTxValid )
Description
Arbitrate for the next VC value based upon current VC value and status of valid inputs
- unnamed: ( pgpTxClk )
Description
Lock in the status of the last cell transmitted
- unnamed: ( pgpTxClk )
Description
Detect frame transmit timeout, enabled only in VC non interleave mode