Visible to Intel only — GUID: nik1411442161640
Ixiasoft
Visible to Intel only — GUID: nik1411442161640
Ixiasoft
3.6. Direct IQ Interface
This interface is Avalon-ST compliant with a ready latency value of 1.
You can alter the transmit latency with the Auxiliary and direct interfaces write latency cycle(s) parameter.
Direct IQ RX Interface | ||
---|---|---|
Signal Name |
Direction |
Description |
iqN_rx_valid[C:0] | Output | Each asserted bit indicates the corresponding byte on the current iq_rx_data bus is valid I/Q data. |
iqN_rx_data[D:0] | Output | I/Q data received from the CPRI frame. The iq_rx_valid signal indicates which bytes are valid I/Q data bytes. |
Direct IQ TX Interface | ||
Signal Name |
Direction |
Description |
iqN_tx_ready[C:0] | Output | Each asserted bit indicates the IP core is ready to read I/Q data from the corresponding byte of iq_tx_data on the next clock cycle. |
iqN_tx_valid[C:0] | Input | Write valid for iq_tx_data. Assert bit [n] to indicate that the corresponding byte on the current iq_tx_data bus is valid I/Q data. |
iqN_tx_data[D:0] | Input | I/Q data to be written to the CPRI frame. The IP core writes the individual bytes of the current value on the iq_tx_data bus to the CPRI frame based on the iq_tx_ready signal from the previous cycle, and the iq_tx_valid signal in the current cycle. |
The aux_rx_x and aux_rx_seq signals are not part of this interface and are available only if you turn on the AUX interface in your CPRI IP core variation. However, their presence in the timing diagram explains the timing of the iq_rx_valid output signal that you use to identify the clock cycles with valid I/Q data.
The aux_tx_x and aux_tx_seq signals are not part of this interface and are available only if you turn on the AUX interface in your CPRI IP variation. However, their presence in the timing diagram explains the timing of the iq_tx_ready output signal that you use to identify the clock cycles when you can write I/Q data to the CPRI frame. Note that the write latency is two cpri_clkout clock cycles in this example.