High Bandwidth Memory (HBM2) Interface FPGA IP User Guide

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ID 683189
Date 3/29/2024
Public
Document Table of Contents
Document Table of Contents x
1. About the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP 2. Introduction to High Bandwidth Memory 3. Stratix® 10 HBM2 Architecture 4. Creating and Parameterizing the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP 5. Simulating the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP 6. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Interface 7. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Controller Performance 8. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP User Guide Archives 9. Document Revision History for High Bandwidth Memory (HBM2) Interface FPGA IP User Guide
1. About the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP x
1.1. Release Information
2. Introduction to High Bandwidth Memory x
2.1. HBM2 in Intel® Stratix® 10 Devices 2.2. HBM2 DRAM Structure 2.3. Stratix® 10 HBM2 Features 2.4. Stratix® 10 HBM2 Controller Features
3. Stratix® 10 HBM2 Architecture x
3.1. Stratix® 10 HBM2 Introduction 3.2. Stratix® 10 UIB Architecture 3.3. Stratix® 10 HBM2 Controller Architecture
3.3. Stratix® 10 HBM2 Controller Architecture x
3.3.1. Stratix® 10 HBM2 Controller Details
4. Creating and Parameterizing the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP x
4.1. Creating an Quartus® Prime Pro Edition Project for High Bandwidth Memory (HBM2) Interface FPGA IP 4.2. Parameterizing the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP 4.3. Pin Planning for the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP
4.2. Parameterizing the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP x
4.2.1. General Parameters for High Bandwidth Memory (HBM2) Interface Intel® FPGA IP 4.2.2. FPGA I/O Parameters for High Bandwidth Memory (HBM2) Interface Intel® FPGA IP 4.2.3. Controller Parameters for High Bandwidth Memory (HBM2) Interface Intel® FPGA IP 4.2.4. Diagnostic Parameters for High Bandwidth Memory (HBM2) Interface Intel® FPGA IP 4.2.5. Example Designs Parameters for High Bandwidth Memory (HBM2) Interface Intel® FPGA IP 4.2.6. Register Map IP-XACT Support for HBM2 IP
5. Simulating the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP x
5.1. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Example Design 5.2. Simulating High Bandwidth Memory (HBM2) Interface Intel® FPGA IP with ModelSim* and Questa* 5.3. Simulating High Bandwidth Memory (HBM2) Interface Intel® FPGA IP with Synopsys VCS* 5.4. Simulating High Bandwidth Memory (HBM2) Interface Intel® FPGA IP with Riviera-PRO* 5.5. Simulating High Bandwidth Memory (HBM2) Interface Intel® FPGA IP with Cadence Xcelium* Parallel Simulator 5.6. Simulating High Bandwidth Memory (HBM2) Interface Intel® FPGA IP for High Efficiency 5.7. Simulating High Bandwidth Memory (HBM2) Interface IP Instantiated in Your Project
6. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Interface x
6.1. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP High Level Block Diagram 6.2. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Controller Interface Signals 6.3. User AXI Interface Timing 6.4. User APB Interface Timing 6.5. User-controlled Accesses to the HBM2 Controller 6.6. Soft AXI Switch
6.2. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Controller Interface Signals x
6.2.1. Clock Signals 6.2.2. Reset Signals 6.2.3. Calibration Status Signals 6.2.4. Memory Interface Signals 6.2.5. User-interface Signals 6.2.6. AXI User-interface Signals 6.2.7. Sideband APB Interface 6.2.8. Avalon® Memory-Mapped (AVMM) Interface Signals
6.3. User AXI Interface Timing x
6.3.1. AXI Write Transaction 6.3.2. AXI Read Transaction 6.3.3. Improving User Logic to HBM2 Controller AXI Interface Timing
6.4. User APB Interface Timing x
6.4.1. Advanced Peripheral Bus Protocol 6.4.2. APB Interface Timing
6.5. User-controlled Accesses to the HBM2 Controller x
6.5.1. User-controlled Refreshes 6.5.2. Temperature and Calibration Status Readout 6.5.3. Controller Idle State Status 6.5.4. Power Down Status 6.5.5. ECC Error Status 6.5.6. User Interrupt 6.5.7. ECC Error Correction and Detection
6.5.6. User Interrupt x
6.5.6.1. Interrupt Enable and Conditions for Interrupt Generation 6.5.6.2. Interrupt Status 6.5.6.3. Error Valid Status
6.6. Soft AXI Switch x
6.6.1. AXI Switch Selection in HBM2 IP Catalog GUI
7. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Controller Performance x
7.1. High Bandwidth Memory (HBM2) DRAM Bandwidth 7.2. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP HBM2 IP Efficiency 7.3. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Latency 7.4. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Timing 7.5. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP DRAM Temperature Readout
1. About the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP
2. Introduction to High Bandwidth Memory
3. Stratix® 10 HBM2 Architecture
4. Creating and Parameterizing the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP
5. Simulating the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP
6. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Interface
7. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP Controller Performance
8. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP User Guide Archives
9. Document Revision History for High Bandwidth Memory (HBM2) Interface FPGA IP User Guide

7.2. High Bandwidth Memory (HBM2) Interface Intel® FPGA IP HBM2 IP Efficiency

The efficiency of the High Bandwidth Memory (HBM2) Interface Intel® FPGA IP estimates data bus utilization at the AXI interface. The AXI4 protocol supports independent write and read address and data channel and accepts concurrent write and read transactions. Calculated efficiency values take into consideration that the core clock frequency and the memory clock frequency are different. The HBM2 IP design example includes an efficiency monitor that reports the efficiency and the minimum latency observed in the transactions that are simulated. You can enable the efficiency monitor on the Diagnostics tab of the HBM2 IP parameter editor.

The following equation represents the HBM2 controller efficiency:

Efficiency = ((Write transactions + Read transactions accepted by HBM2 controller)/total valid transaction count) * (core clk frequency * 2/HBM2 interface frequency) * 100
  • Write transactions – Refers to user write data transactions that the HBM2 controller accepts (user-asserted AXI WVALID and corresponding controller-asserted AXI WREADY).
  • Read transactions – Refers to user read data transactions that the HBM2 controller has processed (controller-asserted AXI RVALID and corresponding user-asserted AXI RREADY).
  • Total valid transaction count – Total transaction time after first valid transaction has been issued.
  • Core frequency (MHz) – The frequency at which user logic operates. The core operates at a lower frequency than the HBM2 interface.
  • HBM2 interface frequency (MHz) - The frequency at which the HBM2 interface operates.

The HBM2 controller provides high efficiency for any given address pattern from the user interface. The controller efficiently schedules incoming commands, avoiding frequent precharge and activate commands as well as frequent bus turn-around when possible.

Factors Affecting Controller Efficiency

Several factors can affect controller efficiency. For best efficiency, you should consider these factors in your design:

  • User-interface frequency vs HBM2 interface frequency - The frequency of user logic in the FPGA fabric plays an important role in determining HBM2 memory efficiency, as shown in the example above.
  • Controller Settings
    • Disable the Reorder Buffer in the Controller Settings to achieve improved efficiency. (However, if the application requires that read data be provided in the same order as the read requests, then it is preferable to enable the Reorder Buffer.)
    • Burst length - The pseudo-BL8 mode helps to ensure shorter memory access timing between successive BL4 transactions, to improve controller efficiency.
  • Traffic Patterns - Traffic patterns play an important role in determining controller efficiency.
    • Sequential vs random DRAM addresses: Sequential addresses enable the controller to issue consecutive write requests to an open page and help to achieve high controller efficiency. Random addresses require constant PRECHARGE/ACTIVATE commands and can reduce controller efficiency.
    • Set the User Auto Precharge Policy to FORCED and set the awuser/aruser signal on the AXI interface to HIGH to enable Auto Precharge for random transactions. For sequential transactions, set the Auto Precharge Policy to HINT.
    • Sequential Read only or Write Only transactions: Sequential read-only or write-only transactions see higher efficiency as they avoid bus turnaround times of the DRAM bi-directional data bus.
  • AXI Transaction IDs – Use of different AXI transaction IDs helps the HBM2 controller schedule the transactions for high efficiency. Use of the same AXI transaction ID preserves command order and may result in lower efficiency.
  • Temperature – There are two main temperature effects that reduce the bandwidth available for data transfers in the Stratix® 10 HBM2 interface:
    • The HBM2 is exceeding a temperature threshold set in the General > Threshold temperature for AXI throttling parameter, along with a value for the AXI throttling ratio.
    • Above 85°C, HBM2 refreshes occur more frequently, so there is less bandwidth available for data transfers. At 85°C, the refresh rate is 2×, and at 95°C, 4× more frequent than the standard refresh time interval of 7.8 microseconds.
    The HBM2 TEMP register value can be read back via the AXI APB bus to help with the correlation of memory refreshes, temperature, and data bandwidth.
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