Double Data Rate I/O (ALTDDIO_IN, ALTDDIO_OUT, and ALTDDIO_BIDIR) IP Cores User Guide

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ID 683148
Date 6/19/2017
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Document Table of Contents
Document Table of Contents x
1. Double Data Rate I/O (ALTDDIO_IN, ALTDDIO_OUT, and ALTDDIO_BIDIR) IP Cores User Guide
1. Double Data Rate I/O (ALTDDIO_IN, ALTDDIO_OUT, and ALTDDIO_BIDIR) IP Cores User Guide x
1.1. ALTDDIO Features 1.2. ALTDDIO Common Applications 1.3. ALTDDIO Resource Utilization and Performance 1.4. ALTDDIO Parameter Settings 1.5. ALTDDIO Functional Description 1.6. Design Example: 8-Bit DDR Divider Using ALTDDIO_BIDIR 1.7. ALTDDIO_IN IP Core Signals 1.8. ALTDDIO_OUT IP Core Signals 1.9. ALTDDIO_BIDIR IP Core Signals 1.10. Verilog HDL Prototype 1.11. VHDL Component Declaration 1.12. VHDL LIBRARY-USE Declaration 1.13. Double Data Rate I/O (ALTDDIO_IN, ALTDDIO_OUT, and ALTDDIO_BIDIR) IP Cores User Guide Archives 1.14. Document Revision History
1.2. ALTDDIO Common Applications x
1.2.1. DDR SDRAM, DDR2 SDRAM and RLDRAM II Memory 1.2.2. QDR SRAM and QDRII SRAM Memory Interfaces 1.2.3. High-Speed Interface Applications
1.5. ALTDDIO Functional Description x
1.5.1. DDR Device Configuration 1.5.2. DDR I/O Timing
1.5.1. DDR Device Configuration x
1.5.1.1. Input Configuration 1.5.1.2. Output Configuration 1.5.1.3. Bidirectional Configuration
1.6. Design Example: 8-Bit DDR Divider Using ALTDDIO_BIDIR x
1.6.1. Generate a Divider Using ALTDDIO_BIDIR 1.6.2. Create a Divider 1.6.3. Implement the Divider Design 1.6.4. Functional Results—Simulate the Divider Design in the ModelSim* - Intel® FPGA Edition Software
1.6.1. Generate a Divider Using ALTDDIO_BIDIR x
1.6.1.1. Create the ALTDDIO_BIDIR IP Core 1.6.1.2. Create the LPM_DIVIDE IP core
1. Double Data Rate I/O (ALTDDIO_IN, ALTDDIO_OUT, and ALTDDIO_BIDIR) IP Cores User Guide

1.5.1.1. Input Configuration

When the IOE is configured as an input pin, input registers AI and BI and latch CI implement the input path for DDR I/O.
Figure 1. Input DDR I/O Path Configuration for a Stratix Series or APEX II DeviceThis figure shows an IOE configured for DDR inputs for a Stratix® series or APEX™ II device.
Note: On the falling edge of the clock, the negative-edge triggered register BI acquires the first data bit. On the corresponding rising edge of the clock, the positive-edge triggered register AI acquires the second data bit. For a successful data transfer to the logic array, the latch CI synchronizes the data from register BI to the positive edge of the clock.
Figure 2. Stratix II IOE in DDR Input I/O ConfigurationThis figure shows an IOE configured for DDR inputs for a Stratix® or Stratix®  II device.
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