Interlaken (2nd Generation) Intel® FPGA IP User Guide

ID 683396
Date 9/26/2022
Public
Document Table of Contents

5.2. Transmit User Interface Signals

Table 29.  Transmit User Interface SignalsThe input signals are synchronous to clk_tx_commom and output signals are synchronous to clk_rx_common.
Signal Name Feature Support Width (Bits) I/O Direction Description
itx_chan ILK 8 Input Transmit logic channel number for the first segment chunk. The IP core supports up to 256 channels. The IP core samples this value only when a bit of itx_sop or itx_sob is high and itx_num_valid has a non-zero value.
ILA [Number of lanes-1:0] Indicates one of two channel numbers associated with the data burst following control symbol. Valid when itx_sop is equal to 1 for corresponding symbol.
itx_chan1 ILK only 8 Input Transmit logic channel number for the second segment chunk. The IP core supports up to 256 channels. DUAL or QUAD segment interface defines this signal. The IP core samples this value only when a bit of itx_sop or itx_sob is high and itx_num_valid has a non-zero value.
itx_num_valid ILK only Variable Input Indicates the number of valid 64-bit words in the current packet in the current data symbol. This signal is not available if you turn on Enable Interlaken Look-aside mode in the Interlaken parameter editor. The width of the itx_num_valid depends on the parameter number of words and Number of segments

For single segment,

  • If number of words=4, then width=3 using itx_num_valid[2:0]
  • If number of words=8, then width=4 using itx_num_valid[7:4]
  • If number of words=16, then width=5 using itx_num_valid[9:5]
For multi-segment,
  • If number of words=8, then width=8 using itx_num_valid[7:4] (first segment chunk) and itx_num_valid[3:0] (second segment chunk)
  • If number of words=16, then width=10 using itx_num_valid[9:5] (first segment chunk) and itx_num_valid[4:0] (second segment chunk)
If number of words is equal to 8 and Number of segments is equal to 2:
  • itx_num_valid[7:4] indicates the number of valid words in itx_din_words[511:0]. The value can vary from 4’b0000 to 4’b1000.
  • itx_num_valid[3:0] indicates the number of valid words in itx_din_words[255:0]. The value can vary from 4’b0000 to 4'b0100.
In non-valid cycle, the value of itx_num_valid[7:4] and itx_num_valid[3:0] must be set to 4’b0000.

In the end of burst cycle (itx_eob=1), if the value of itx_num_valid[7:4] is equal to or less than 4'0100 and the parameter Number of Segments is set to 2 , then the value of itx_num_valid[3:0] can be set to values from 4'b0000 to 4'b0100. See the table below for valid values. If the value of itx_num_valid[3:0] is set to non-zero, you must set the value of itx_sob[0] to 1'b1.
itx_num_valid[7:4] itx_num_valid[3:0]
1, 2, 3, 4 0, 1, 2, 3, 4
5, 6, 7, 8 0
If number of words is equal to 8 and Number of segments is equal to 4:
  • itx_num_valid[7:4] indicates the number of valid words in itx_din_words[511:0]. The value can vary from 4’b0000 to 4’b1000.
  • itx_num_valid[3:0] indicates the number of valid words in itx_din_words[383:0]. The value can vary from 4’b0000 to 4’b0110.
In non-valid cycle, the value of itx_num_valid[7:4] and itx_num_valid[3:0] must be set to 4’b0000.
In the end of burst cycle (itx_eob=1), if the value of itx_num_valid[7:4] is equal to or less than 4'0110 and the parameter Number of segments is set to 4 , then the value of itx_num_valid[3:0] can be set to 4'b0000 to 4'b0110. See the table below for valid values. If the value of itx_num_valid[3:0] is set to non-zero, you must set the value of itx_sob[0] to 1'b1.
itx_num_valid[7:4] itx_num_valid[3:0]
1, 2 0, 1, 2, 3, 4, 5, 6
3, 4 0, 1, 2, 3, 4
5, 6 0, 1, 2
7, 8 0
If number of words is equal to 16 and Number of segments is equal to 2:
itx_num_valid[9:5] itx_num_valid[4:0]
1, 2, 3, 4, 5, 6, 7, 8 0, 1, 2, 3, 4, 5, 6, 7, 8
9, 10, 11, 12, 13, 14, 15, 16 0
If number of Words is equal to 16 and Number of segments is equal to 4:
itx_num_valid[9:5] itx_num_valid[4:0]
1, 2, 3, 4 0 to 12
5, 6, 7, 8 0 to 8
9, 10, 11, 12 0 to 4
13, 14, 15, 16 0
itx_eob ILK only 1 Input Indicates the current data symbol contains the end of the burst (EOB) for the first segment chunk.

This signal is not available if you turn on Enable Interlaken Look-aside mode in the Interlaken parameter editor.

This signal is used in SINGLE, DUAL or QUAD segment mode.

Whenever parameter TX_PKTMOD_ONLY is set to 0, you must provide this signal. Otherwise, when parameter TX_PKTMOD_ONLY is set to 1, the IP core ignores this signal. You are responsible to comply with the BurstMax and BurstMin setting.

itx_eob1 ILK only 1 Input Indicates the current data symbol contains the end of the burst (EOB) for the second segment chunk.

This signal is used in DUAL or QUAD segment mode.

Whenever parameter TX_PKTMOD_ONLY is set to 0, you must provide this signal. Otherwise, when parameter TX_PKTMOD_ONLY is set to 1, the IP core ignores this signal. You are responsible to comply with the BurstMax and BurstMin setting.

itx_eopbits ILK 4 Input Number of bytes at the end of packet for the first segment chunk. Indicates whether the current data symbol contains the end of a packet (EOP) with or without an error, and specifies the number of valid bytes in the current end-of-packet, non-error 8-byte data word, if relevant.
You must set the value of itx_eopbits as following:
  • 4b’0000: no end of packet, no error.
  • 4b’0001: Error and end of packet.
  • 4b’1xxx: End of packet. xxx indicates the number of valid bytes in the final valid 8-byte word of the packet, as following:
    • 000: all 8 bytes are valid.
    • 001: 1 byte is valid.
    • 111: 7 bytes are valid.
All other values (4'b01xx, 4'b001x) are undefined. The valid bytes always start in bit positions [63:56] of the final valid data word of the packet.
ILA [Number of lanes*4-1:0] Specifies the number of valid bytes of the corresponding data symbol and indicates the end of packet transfer (EOP).
You must set the value of itx_eopbits as following:
  • 4b’0000: no end of packet, no error.
  • 4b’0001: Error and end of packet.
  • 4b’1xxx: End of packet. xxx indicates the number of valid bytes in the final valid 8-byte word of the packet, as following:
    • 000: all 8 bytes are valid.
    • 001: 1 byte is valid.
    • 111: 7 bytes are valid.
All other values (4'b01xx, 4'b001x) are undefined.
itx_eopbits1 ILK only 4 Input Number of bytes at the end of packet for the second segment chunk. Indicates whether the current data symbol contains the end of a packet (EOP) with or without an error, and specifies the number of valid bytes in the current end-of-packet, non-error 8-byte data word, if relevant.
You must set the value of itx_eopbits1 as following:
  • 4b’0000: no end of packet, no error.
  • 4b’0001: Error and end of packet.
  • 4b’1xxx: End of packet. xxx indicates the number of valid bytes in the final valid 8-byte word of the packet, as following:
    • 000: all 8 bytes are valid.
    • 001: 1 byte is valid.
    • ...
    • 111: 7 bytes are valid.
All other values (4'b01xx, 4'b001x) are undefined. The valid bytes always start in bit positions [63:56] of the final valid data word of the packet.
itx_sob ILK only 1, 2 or 4 Input Indicates the current data symbol contains the start of a burst (SOB).

This signal is not available if you turn on Enable Interlaken Look-aside mode in the Interlaken parameter editor.

If the IP core is in Interleaved mode, you are responsible for providing this start of the burst signal. If the IP core is in Packet mode, the IP core ignores this signal. The IP core samples the itx_chan signal during this cycle.
  • [1]— single segment
  • [1:0]—dual segment
  • [3:0]—four segment

{segment 3, segment 2, segment 1, segment 0} defines the segment order with segment 3 starts at the most significant bit location.

Using four segment as example, the signal has the following valid values:
  • [3]: indicates SOB for the first segment chunk.
  • [2:0]: only one bit can be set to indicate SOB for the second segment chunk.

For example:

If number of words= 16, Number of segments =4, tx_num_valid[9:5] =3, tx_num_valid[4:0]= 9, then the second segment starts at word[11], sob[3:0]= 4'1100

If number of words= 16, Number of segments=4, tx_num_valid[9:5] =9, tx_num_valid[4:0]= 4, then the second segment starts at word[3], sob[0]= 4'1001

itx_sop ILK 1, 2 or 4 Input Indicates the current data symbol on itx_din_words contains the start of a packet (SOP).
  • [1]— single segment
  • [1:0]—dual segment
  • [3:0]—four segment

{segment 3, segment 2, segment 1, segment 0} defines the segment order with segment 3 starts at the most significant bit location.

Using four segment as example, the signal has the following valid values:
  • [3]: indicates SOP for the first segment chunk.
  • [2:0]: only one bit can be set to indicate SOP for the second segment chunk.

For example:

If number of words, Number of segments=4, tx_num_valid[9:5] =3, tx_num_valid[4:0]= 9, then the second segment starts at word[11], sop[3:0]= 4'1100

If number of words= 16, Number of segments=4, tx_num_valid[9:5] =9, tx_num_valid[4:0]= 4, then the second segment starts at word[3], sop[0]= 4'1001

ILA [Number of lanes-1:0] Each bit indicates the SOP for the data burst following corresponding control symbol.
itx_din_words ILK Variable Input The 64-bit words of input data (one data symbol). The width of the itx_dout_words depends on the parameter number of words.
  • If number of words=4, then width=256 bits.
  • If number of words=8, then width=512 bits.
  • If number of words=16, then width=1024 bits.

The first and last data word is in [511:448] and [63:0] respectively.

ILA [Number of lanes*64-1:0]

The 64-bits words of input data (one data symbol). When itx_idle is equal to one, the ILA IP core ignores matching data word in itx_din_words.

The width of the itx_din_words depends on parameter number of lanes:
  • If number of lanes=4, then width=256 bits.
  • If number of lanes=6, then width=284 bits.
  • If number of lanes=8, then width=512 bits.
  • If number of lanes=10, then width=640 bits.
  • If number of lanes=12, then width=768 bits.

Example: For 8 lanes, the first data word is in [511:448] and last data word is in [63:0].

itx_calendar ILK only N * 16 Input Multiple pages (16 bits per page) of calendar input bits. The IP core copies these bits to the in-band flow control bits in N control words that it sends on the Interlaken link. N is the value of the Number of calendar pages parameter, which can be any of 1, 2, 4, 8. or 16. This signal is synchronous with tx_usr_clk, although it is not part of the user data transfer protocol.
itx_ready ILK 1 Output Flow control signal to back pressure transmit traffic. When this signal is high, you can send traffic to the IP core. When this signal is low, you should stop sending traffic to the IP core within one to four cycles. You should provide itx_num_valid only after itx_ready is asserted.
ILA The signal indicates IP readiness to accept user data. When this signal is high, you can send traffic to the IP core. When this signal is low, it indicates tx_lanes_aligned and/or rx_lanes_aligned deasserted.
itx_ch0_xon ILA only 1 Output Indicates channel 0 flow control.

This signal is available only if you turn on Enable Interlaken Look-aside mode in the Interlaken parameter editor.

itx_ch1_xon ILA only 1 Output Indicates channel 1 flow control.

This signal is available only if you turn on Enable Interlaken Look-aside mode in the Interlaken parameter editor.

itx_valid ILA only 1 Input Valid signal for entire input bus. The pattern of itx_valid should match that of itx_credit. The latency between itx_credit anditx_valid should be fixed and specified by the parameter TX_CREDIT_LATENCY.

This signal is available only if you turn on Enable Interlaken Look-aside mode in the Interlaken parameter editor.

itx_idle ILA only [Number of lanes-1:0] Input Each bit indicates unused 64-bit words in the current data symbol and it is also not part of a burst. The IP inserts IDLE control word in this location. The IDLE equals to one may imply the end of a previous burst. It is not necessary to have IDLE between bursts. It is legal to immediately start a new burst after last data word of previous burst.

This signal is available only if you turn on Enable Interlaken Look-aside mode in the Interlaken parameter editor.

itx_ctrl ILA only [Number of lanes*29-1:0] Input Eight 29 bits itx_ctrl signal indicates the application specific 0 (15 bits), specific 1 (6 bits) and specific 2 (8 bits) data for ILA. ILA IP core samples this value only when associated itx_sop is valid. The most significant 29 control bits data is aligned with the most significant bit of itx_sop. {specific 0, specific 1, specific 2} = {[28:14],[13:8],[7:0]}

This signal is available only if you turn on Enable Interlaken Look-aside mode in the Interlaken parameter editor.

itx_credit ILA only 1 Output Flow control signal to give backpressure to the transmit traffic. User logic asserts itx_valid after TX_CREDIT_LATENCY cycles regardless of itx_ready state and/or existence of user data.

This signal is available only if you turn on Enable Interlaken Look-aside mode in the Interlaken parameter editor.

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