5.2. Transmit User Interface Signals
Signal Name | Width (Bits) | I/O Direction | Available In | Description | ||||||||||||||||||||||||||||||||
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itx_chan | 8 | Input | Interlaken mode | 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 itx_sob is high and itx_num_valid has a non-zero value. | ||||||||||||||||||||||||||||||||
[Number of lanes - 1] | Interlaken Look-aside mode | 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 | 8 | Input | Interlaken mode | 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 itx_sob is high and itx_num_valid has a non-zero value. | ||||||||||||||||||||||||||||||||
itx_num_valid | Variable | Input | Interlaken mode | Indicates the number of valid 64-bit words in the current packet in the current data symbol. The width of the itx_num_valid depends on the parameter number of words and Number of segments For single segment,
For multi-segment,
If number of words is equal to 8 and Number of segments is equal to 2:
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.
If number of words is equal to 8 and Number of segments is equal to 4:
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.
If number of words is equal to 16 and Number of segments is equal to 2:
If number of Words is equal to 16 and Number of segments is equal to 4:
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itx_eob | 1 | Input | Interlaken mode | Indicates the current data symbol contains the end of the burst (EOB) for the first segment chunk. This signal is used in SINGLE, DUAL or QUAD segment mode. When itx_eopbits has valid value of 4’b1xxx or 4’b0001, the itx_eob is valid too, but not vice-versa. 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. |
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itx_eob1 | 1 | Input | Interlaken mode | 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. When itx_eopbits1 has valid value of 4’b1xxx or 4’b0001, the itx_eob1 is valid too, but not vice-versa. 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. |
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itx_eopbits | 4 | Input | Interlaken mode | 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:
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[(Number of lanes * 4) -1 : 0] | Interlaken Look-aside mode | 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:
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itx_eopbits1 | 4 | Input | Interlaken mode | 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. This signal is used in DUAL or QUAD segment mode.
You must set the value of itx_eopbits1 as following:
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itx_sob | Variable | Input | Interlaken mode | Indicates the current data symbol contains the start of a burst (SOB). 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.
{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:
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]= 4'1100If 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 |
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itx_sop | Variable | Input | Interlaken mode | Indicates the current data symbol on itx_din_words contains the start of a packet (SOP).
{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:
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]= 4'1100If 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 |
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[(Number of lanes -1) : 0] | Interlaken Look-aside mode | Each bit indicates the start of a packet (SOP). | ||||||||||||||||||||||||||||||||||
itx_din_words | Variable | Input | Interlaken mode | The 64-bit words of input data (one data symbol). The width of the itx_dout_words depends on the parameter number of words.
The first and last data word is in [511:448] and [63:0] respectively. |
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[(Number of lanes * 64 -1) : 0] | Interlaken Look-aside mode | Eight 64-bits words of input data (one data symbol). When itx_idle or tx_sob is one, the Interlaken IP core ignores matching data word in itx_din_words. The first data word is in [511:448] and last data word is in [63:0]. | ||||||||||||||||||||||||||||||||||
itx_calendar | N * 16 | Input | Interlaken mode | 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 | 1 | Output | Interlaken mode | 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. | ||||||||||||||||||||||||||||||||
Interlaken Look-aside mode | 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. |
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itx_ch0_xon | 1 | Output | Interlaken Look-aside mode | Indicates channel 0 flow control. | ||||||||||||||||||||||||||||||||
itx_ch1_xon | 1 | Output | Interlaken Look-aside mode | Indicates channel 1 flow control.Indicates channel 0 flow control. | ||||||||||||||||||||||||||||||||
itx_valid | 1 | Input | Interlaken Look-aside mode | Valid signal for entire input bus. The pattern of itx_valid should match that of itx_credit. The latency between itx_credit and itx_valid should be fixed and specified by the parameter TX_CREDIT_LATENCY. | ||||||||||||||||||||||||||||||||
itx_idle | [(Number of lanes -1) : 0] | Input | Interlaken Look-aside mode | 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. |
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itx_ctrl | [(Number of lanes * 29 -1) : 0] | Input | Interlaken Look-aside mode | Eight 29 bits signal indicates the application specific 0 (15 bits), specific 1 (6 bits), and specific 2 (8 bits) data for Interlaken Look-aside mode. This signal can be valid only when itx_sop is asserted. 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]}. |
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itx_credit | 1 | Output | Interlaken Look-aside mode | 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. |