3.3. JESD204C Design Example Signals
| Signal | Direction | Description | 
|---|---|---|
| Clocks and Resets | ||
| mgmt_clk | Input |   100 MHz clock for system management.  |  
     
| refclk_xcvr | Input |   PLL/CDR reference clock for transceiver PHY.  |  
     
| refclk_core | Input |   Core PLL reference clock. Applies the same clock frequency as refclk_xcvr.  |  
     
| global_rst_n | Input |   Global reset signal from the push button. This reset is an active low signal and the deassertion of this signal is synchronous to the rising-edge of mgmt_clk.  |  
     
| in_sysref | Input |   SYSREF signal from external SYSREF generator for JESD204C Subclass 1 implementation.  |  
     
| sysref_out | Output |   SYSREF signal for JESD204C Subclass 1 implementation generated by the FPGA device for design example link initialization purpose only.  |  
     
| Signal | Direction | Description | 
| SPI | ||
| spi_SS_n[2:0] | Output |   Active low, SPI slave select signal.  |  
     
| spi_SCLK | Output |   SPI serial clock.  |  
     
|  spi_sdio 
        
        Note: When Generate 3-Wire SPI Module option is enabled. 
          |  
      Input/Output |   Output data from the master to external slave. Input data from external slave to master.  |  
     
|  spi_MISO 
        
        Note: When Generate 3-Wire SPI Module option is not enabled. 
          |  
      Input |   Input data from external slave to the SPI master.  |  
     
|  spi_MOSI 
        
        Note: When Generate 3-Wire SPI Module option is not enabled. 
          |  
      Output |   Output data from SPI master to the external slave.  |  
     
| Signal | Direction | Description | 
| ADC/DAC | ||
| tx_serial_data[LINK*L-1:0] | Output |   Differential high speed serial output data to DAC. The clock is embedded in the serial data stream.  |  
     
| tx_serial_data_n[LINK*L-1:0] | ||
| rx_serial_data[LINK*L-1:0] | Input | Differential high speed serial input data from ADC. The clock is recovered from the serial data stream. | 
| rx_serial_data_n[LINK*L-1:0] | ||
| Signal | Direction | Description | 
| General Purpose I/O | ||
| user_led[3:0] | Output |   Indicates the status for the following conditions: 
  |  
     
| user_dip[3:0] | Input |   User mode DIP switch input: 
  |  
     
|   Signal  |  
        Direction  |  
        Description  |  
     
| Out-of-band (OOB) and Status | ||
| rx_patchk_data_error[LINK-1:0] |   Output  |  
        When this signal is asserted, it indicates pattern checker has detected error.  |  
     
| rx_link_error[LINK-1:0] |   Output  |  
        When this signal is asserted, it indicates JESD204C RX IP has asserted interrupt.  |  
     
| tx_link_error[LINK-1:0] |   Output  |  
        When this signal is asserted, it indicates JESD204C TX IP has asserted interrupt.  |  
     
| emb_lock_out |   Output  |  
        When this signal is asserted, it indicates JESD204C RX IP has achieved EMB lock.  |  
     
| sh_lock_out |   Output  |  
        When this signal is asserted, it indicates JESD204C RX IP sync header is locked.  |  
     
|   Signal  |  
        Direction  |  
        Description  |  
     
| Avalon Streaming | ||
| rx_avst_valid[LINK-1:0] |   Input  |  
        Indicates whether the converter sample data to the application layer is valid or invalid. 
  |  
     
| rx_avst_data[LINK-1:0][(TOTAL_SAMPLE*N)-1:0] |   Input  |  
        Converter sample data to the application layer.  |