5.2. Transmit User Interface Signals
Signal Name | Width (Bits) | I/O Direction | Description | ||||||||||||||||||||||||||||||||
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itx_chan | 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 itx_sob is high and itx_num_valid has a non-zero value. | ||||||||||||||||||||||||||||||||
itx_chan1 | 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 itx_sob is high and itx_num_valid has a non-zero value. | ||||||||||||||||||||||||||||||||
itx_num_valid | Variable | Input | 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 | 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 | 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 | 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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itx_eopbits1 | 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:
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itx_sob | Variable | Input | 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 | 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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itx_din_words | 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.
The first and last data word is in [511:448] and [63:0] respectively. |
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itx_calendar | 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 | 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. |