Intel® Quartus® Prime Pro Edition User Guide: Design Recommendations

ID 683082
Date 6/20/2022

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Document Table of Contents

1.8. Recommended HDL Coding Styles Revision History

The following revisions history applies to this chapter:

Document Version Intel® Quartus® Prime Version Changes
2021.10.04 21.3
  • Added new Inferring FIFOs in HDL Code topic and linked to FIFO Intel FPGA IP User Guide.
  • Added new Dual Clock FIFO Example in Verilog HDL topic.
  • Added new Dual Clock FIFO Timing Constraints topic.
2021.06.21 21.2
  • Updated Inferring Shift Registers in HDL Code for Intel® Stratix® 10 and Intel® Agilex™ devices.
  • Updated wording of Controlling RAM Inference and Implementation for clarity.
2019.09.30 19.3
  • Updated Simple Dual-Port Synchronous RAM with Byte Enable examples.
  • Updated True Dual-Port Synchronous RAM examples.
  • Updated Verilog HDL Single-Bit Wide Shift Register example from 64 to 69 bits.
  • Updated VHDL Single-Bit Wide Shift Register example from 67 to 69 bits.
  • Updated Verilog HDL 8-Bit Wide Shift Register with Evenly Spaced Taps from 64 to 254 bits.
2018.09.24 18.1
  • Added "State Machine Power-Up" topic.
  • Updated "Designing with Low-Level Primitives" to remove support for carry and cascade chains using CARRY, CARRY_SUM, and CASCADE primitives.
  • Renamed topic: "Use the Device Synchronous Load (sload) Signal to Initialize" to "Initialize the Device with the Synchronous Load (sload) Signal"
2017.11.06 17.1
  • Described new no_ram synthesis attribute.
2017.05.08 17.0
  • Updated example: Verilog HDL Multiply-Accumulator
  • Updated information about use of safe state machine.
  • Revised Check Read-During-Write Behavior.
  • Revised Controlling RAM Inference and Implementation.
  • Revised Single-Clock Synchronous RAM with Old Data Read-During-Write Behavior.
  • Revised Single-Clock Synchronous RAM with New Data Read-During-Write Behavior.
  • Updated and moved template for VHDL Single-Clock Simple Dual Port Synchronous RAM with New Data Read-During-Write Behavior.
  • Revised Inferring ROM Functions from HDL Code.
  • Removed example: VHDL 8-Bit Wide, 64-Bit Long Shift Register with Evenly Spaced Taps.
  • Removed example: Verilog HDL D-Type Flipflop (Register) With ena, aclr, and aload Control Signals
  • Removed example: VHDL D-Type Flipflop (Register) With ena, aclr, and aload Control Signals
  • Added example: Verilog D-type Flipflop bus with Secondary Signals
  • Removed references to 4-input LUT-based devices.
  • Removed references to Integrated Synthesis.
  • Created example: Avoid this VHDL Coding Style.
2016.10.31 16.1
  • Provided corrected Verilog HDL Pipelined Binary Tree and Ternary Tree examples.
  • Implemented Intel rebranding.
2016.05.03 16.0
  • Added information about use of safe state machine.
  • Updated example code templates with latest coding styles.
2015.11.02 15.1
  • Changed instances of Quartus II to Intel® Quartus® Prime .
2015.05.04 15.0 Added information and reference about ramstyle attribute for sift register inference.
2014.12.15 14.1 Updated location of Fitter Settings, Analysis & Synthesis Settings, and Physical Optimization Settings to Compiler Settings.
2014.08.18 14.0.a10
  • Added recommendation to use register pipelining to obtain high performance in DSP designs.
2014.06.30 14.0 Removed obsolete MegaWizard Plug-In Manager support.
November 2013 13.1 Removed HardCopy device support.
June 2012 12.0
  • Revised section on inserting Altera templates.
  • Code update for Example 11-51.
  • Minor corrections and updates.
November 2011 11.1
  • Updated document template.
  • Minor updates and corrections.
December 2010 10.1
  • Changed to new document template.
  • Updated Unintentional Latch Generation content.
  • Code update for Example 11-18.
July 2010 10.0
  • Added support for mixed-width RAM
  • Updated support for no_rw_check for inferring RAM blocks
  • Added support for byte-enable
November 2009 9.1
  • Updated support for Controlling Inference and Implementation in Device RAM Blocks
  • Updated support for Shift Registers
March 2009 9.0
  • Corrected and updated several examples
  • Added support for Arria II GX devices
  • Other minor changes to chapter
November 2008 8.1 Changed to 8-1/2 x 11 page size. No change to content.
May 2008 8.0

Updates for the Intel® Quartus® Prime software version 8.0 release, including:

  • Added information to “RAM
  • Functions—Inferring ALTSYNCRAM and ALTDPRAM Megafunctions from HDL Code” on page 6–13
  • Added information to “Avoid Unsupported Reset and Control Conditions” on page 6–14
  • Added information to “Check Read‑During‑Write Behavior” on page 6–16
  • Added two new examples to “ROM Functions—Inferring ALTSYNCRAM and LPM_ROM Megafunctions from HDL Code” on page 6–28: Example 6–24 and Example 6–25
  • Added new section: “Clock Multiplexing” on page 6–46
  • Added hyperlinks to references within the chapter
  • Minor editorial updates