1. Team Members Xuan Bao Jacob Cox Bryan Fleming Wenzhong Wu 20 February 2009

2.  Switch Fabric moves frames from Receive to Transmit  Uses information from (and provides information to) Table Management  Must be faster for more ports and higher line speeds  Three common designs…

8.  Interfaces with Receive Ports  Consists of two components ◦ Receive Interface (Bryan Fleming) ◦ Receive Handler (Xuan Bao)

9.  Arbitrates between Receive Ports needing service  Round-robin service policy ◦ Valid for 4-port switch with fabric running at 4x line speed

13. Block Diagram

14. Interface Interfaces to Receiver Interface: Output: Data_Read: out std_logic; --read enable signal to Rcv FIFO, handshake Length_Read: out std_logic; -- read enable signal to Rcv length FIFO Packet_Finished: out std_logic; handshake --packet end signal Packet_ Error: out std_logic; --packet error signal Input: Data: in std_logic_vector(7 downto 0); --data bus Packet_Length: in std_logic_vector(11 downto 0); --packet length bus and validsignalbus Connection_Ready: in std_logic_vector; --input handshake Check_Counter: in std_logic_vector(11 downto 0); --Rcv’s counter value, for protecting from counter error Input_Port_Number: in std_logic_vector(1 downto 0); Interfaces to Data FIFO: Output: Data_Output: out std_logic_vector(7 downto 0); --prepare data for transmit side

15. Interface Data_wrreq: out std_logic; --write enable to data FIFO Input: FIFO_Empty: in std_logic; --1 port in from FIFO Interfaces to Table Interface: Output: Address: out std_logic_vector(7 downto 0); --output to address FIFO Address_InputPortNumber: out std_logic_vector(1 downto 0); --expose input port number to address lookup Address_wrreq: out std_logic --write enable to address FIFO Input: Address_FIFO_Empty: in std_logic; Interfaces to Length FIFO Output: Packet_Length_Output: out std_logic_vector(10 downto 0); --expose length information to transmitter handle Length Wrreq: out std_logic;

16. Function 1 Generate hand shake signal for receiver interface 2 Read data and length information from receiver FIFOs 3 Check the validation of a packet to decide either to forward it or drop it 4 Prepare address information for table interface *5 Compare the counter value with receiver side to prevent one point failure (this function is in the original code but not included in the final version)

17. State Machine

18. Data Flow Chart

19. Simulation Results A Valid Pkt Forward Addr, 12 Bytes Finish Reading one Pkt

20. An Invalid Pkt No Output to length and data FIFO Finish Dropping

21.  Wenzhong Wu  Interfaces Switch Fabric Receive Side (Receive Handler) with Table  Interfaces Table with Internal FIFOs for Switch Fabric Transmit Side

23. SF_table_interface data path

26. SF_Table_interface simulation result

27. Simulation result of “SF_table_interface” + “switchmanagement”

28.  Consists of ◦ Comp 1 (Jacob Cox) ◦ Comp 2 (Jacob Cox) ◦ Comp 3 (Jacob Cox) ◦ … ◦ Transmit Port Monitor (Bryan Fleming)

29. 11.. 0 1212 8 3 SF_fifo2xmt_interf ace ODL_empty[ 2] ODL_empty[ 1] ODL_empty[ 0] Clk xmt_dwtreq xmt_lwtreq i_O_FIFO rd_D_FIF O i_O_FIFOi_L_FIFO xmt_wordsuse d i_D_FIFOo_D_xmt i_L_FIFOo_L_xmt reset TRANSMIT PORTSTRANSMIT PORTS 1212 8

30. SF_fifo2xmt_interf ace ODL_empty[ 2] ODL_empty[ 1] ODL_empty[ 0] Clk xmt_dwtreq xmt_lwtreq i_O_FIFO rd_D_FIF O i_O_FIFOi_L_FIFO xmt_wordsuse d i_D_FIFOo_D_xmt i_L_FIFOo_L_xmt reset XMT Data Fifo(0) XMT Length Fifo(0) XMT Length Fifo(1) XMT Length Fifo(2) XMT Length Fifo(3) XMT Data Fifo(3) XMT Data Fifo(2) XMT Data Fifo(1) 1212 8

31. Data Write Request Drop Packets Final Data Packet Write Length

32. Data Enters Data_FIFO 1000 0010 Write Requests to the Transmit FIFOs Number of words already in the Transmit FIFO

33. SF_fifo2xmt_interfac e Clk xmt_dwtreq xmt_lwtreq i_O_FIFO xmt_wordsuse d i_D_FIFOo_D_xmt i_L_FIFO o_L_xmt reset rd_D_FIF O rd_O_FIF O rd_L_FIFO SF_FIFO_monitor ODL_empty[2.. 0] Clk xfer_D_req Send_L i_O_FIFO o_read_ D o_read_L i_L_FIFO xfer_L_re q reset o_read_ O o_L_FIFO 8 CounterC i_count [11-0] Clk o_Snd_L i_read_L reset o_count[11- 0] ODL_empty[ 2] ODL_empty[ 1] ODL_empty[ 0] 1212 & xmt_port_moni tor Clk reset SF_PacketComin g xmt_wordsus ed 1212 SF_PacketLeng th SF_PacketFinish ed SF_dwtre q SF_lwtreq xmt_lwtre q xmt_dwtr eq counter_fifo_monitor_merg er

34. Merger of FIFO_Monitor, Counter, and Port_Monitors results in successful initiation, countdown, and termination of data transfer. Fifo Empty Signals

35. CounterC o_count[11- 0] i_count [11- 0] “x000” Clk o_Snd_L s_snd_L <= '0‘ s_en <=’0’ reset = ‘0' i_read_L = ‘1‘ & reset =‘0’ F s_snd_L <= '0‘ s_en <=’1’ T T F s_count =i_count- 1 & reset =‘0’ T s_snd_L <= ‘1‘ s_en <=’1’ s_count = i_count s_count [11- 0] F s_snd_L reset s_en i_read_L

36. ODL_FIFO = “000” Send_L = ‘1’ s_i_O_FIFO = “000 to 111” reset = ‘1’

37. Idle ODL_FIFO =0000 Reset =0 F T T F Get_Length F Reset =0 T Send_Data F Reset =0 T NS_FIFO<=0000 NS_length<=x00 00 s_o_read_L<=0 s_o_read_O<=0 o_read_D<=0 xfer_D_req<=000 0 xfer_L_req<=000 0 Get_Lengt h Idle NS_FIFO<=i_O_FIFO NS_length<=i_L_FIF O s_o_read_L<=1 s_o_read_O<=1 o_read_D<=0 xfer_D_req<=0000 xfer_L_req<=0000 Send_L =0 F T s_o_read_L<=1 s_o_read_O<=1 o_read_D<=0 Send_Data xfer_D_req<=000 1 xfer__L_req<=000 1 xfer_D_req<=111 0 xfer_L_req<=1110 xfer_D_req<=001 0 xfer_L_req<=0010 xfer_D_req<=010 0 xfer_L_req<=0100 xfer_D_req<=100 0 xfer_L_req<=1000 xfer_D_req<=110 1 xfer_L_req<=1101 xfer_D_req<=111 0 xfer_L_req<=1110 xfer_D_req<=101 1 xfer_L_req<=1011 xfer_D_req<=000 0 xfer_L_req<=0000 CS_FIFO=0000 CS_FIFO=othe r ASM of FIFO_Monitor FSM

38. Read Signals Asserted for Output and Length FIFOs Read Signal Asserted for Data FIFO on the next clock Write signals asserted for Transmitters All FIFOs have Data = 0 Send Length indicates a count is complete

40. Write Signals Asserted two clocks after all FIFOs have data

41. Output Destination Packet Length Fifo Empty Signals Fifo Read Signals Length Write Signals Terminate

42.  Responsible for dropping packets if transmit port queue is too full  Never writes a partial packet into transmit port  Designed for safety, could be further optimized

45.  Naming conventions can make life easier  Version control is good, though it has a learning curve  Other concluding thoughts…