JESD204B IP Core Design Example User Guide

ID 683094
Date 11/06/2017

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Document Table of Contents

1.6. Design Example with RTL State Machine Control Unit

This design example with RTL state machine control unit is the legacy design example that was first released in Quartus II version 13.1. The design example has the following key features:

  • Supports Arria V, Cyclone V, Stratix V, and Arria 10 devices.
  • Purely hardware-implemented control path, no software control features.
  • Lower FPGA core resource utilization compared to Nios II processor control unit design example.
  • Available as a synthesizable design entity and a simulation model.

The design example entity consists of various components that interface with the JESD204B IP core to demonstrate the following features:

  • single or multiple link configuration
  • different LMF settings with scrambling and internal serial loopback enabled
  • interoperability against diverse converter devices
  • dynamic reconfiguration
Figure 4. RTL State Machine Control Unit Design Example Block Diagram

This figure illustrates the high level system architecture of the JESD204B IP core design example.

The list below describes the mechanism of the design example architecture (with reference to the note numbers in the design example block diagram).

  1. For multiple links, the JESD204B IP core is instantiated multiple times. For example, in 2x112 (LMF) configuration, two cores are instantiated, where each core is configured at LMF=112.
  2. The number of pattern generator or pattern checker instances is equivalent to the parameter value of LINK. The data bus width per instance is equivalent to the value of FRAMECLK_DIV*M*S*N.
  3. The number of transport layer instances is equivalent to the parameter value of LINK. The legal value of LINK is 1 and 2. The data bus width per instance is equivalent to the value of FRAMECLK_DIV*M*S*N. The test_mode = 0 signal indicates a normal operation mode, where the assembler takes data from the Avalon-ST source. Otherwise, the assembler takes data from the pattern generator.
  4. The Avalon-ST interface data bus is fixed at 32-bit. The number of 32-bit data bus is equal to the number of lanes (L).
  5. The number of lanes per converter device (L).
  6. You can enable internal serial loopback by setting the rx_seriallpbken input signal. You can dynamically toggle this input signal. When toggled to 1, the RX path takes the serial input from the TX path internally in the FPGA. When toggled to 0, the RX path takes the serial input from the external converter device. During internal serial loopback mode, the assembler takes input from the pattern generator.
  7. A single serial port interface (SPI) master instance can control multiple SPI slaves. The SPI master is a 4-wire instance. If the SPI slave is a 3-wire instance, use a bidirectional I/O buffer in between the master and slave to interface the 4-wire master to 3-wire slave.
  8. The SPI protocol interface. All slaves share the same data lines (MISO and MOSI, or DATAIO). Each slave has its own slave select or chip select line (SS_n).
  9. The PLL takes the device clock from an external clock chip as the input reference. The PLL generates two output clocks (utilizing two output counters from a single VCO). Clock 1 is the frame clock for the transport layer, pattern generator, and pattern checker. Clock 2 is the link clock for the transport and link layer.
  10. The control unit implements a memory initialization file (MIF) method for configuring the SPI. Each MIF corresponds to a separate external converter per device or clock chip. For example, in a system that interacts with both DAC and ADC, two MIFs are needed—one each for DAC and ADC.
  11. The PLL reconfiguration and transceiver reconfiguration controller instances are only required for run time reconfiguration of the data rate.