ALTIOBUF IP Core User Guide

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ID 683471
Date 1/13/2020
Public
Document Table of Contents
Document Table of Contents x
ALTIOBUF IP Core User Guide
ALTIOBUF IP Core User Guide x
Device Family Support ALTIOBUF Features I/O Buffer and Dynamic Delay Integration ALTIOBUF Common Application ALTIOBUF Parameters ALTIOBUF Functional Description ALTIOBUF References ALTIOBUF IP Core User Guide Archives Document Revision History for the ALTIOBUF IP Core User Guide
ALTIOBUF Parameters x
Using the Port and Parameter Definitions
ALTIOBUF Functional Description x
ALTIOBUF Input, Output, and OE Paths
ALTIOBUF Input, Output, and OE Paths x
ALTIOBUF Input Buffer ALTIOBUF Output Buffer ALTIOBUF Bidirectional Buffer Dynamic Delay Chain Valid Values Assignments Necessary For Dynamic Delay Chain Usage
ALTIOBUF Input Buffer x
Differential Mode Pin Naming Convention
ALTIOBUF References x
ALTIOBUF Signals and Parameters: As Input Buffer ALTIOBUF Signals and Parameters: As Output Buffer ALTIOBUF Signals and Parameters: As Bidirectional Buffer Verilog HDL Prototype VHDL Component Declaration VHDL LIBRARY-USE Declaration
ALTIOBUF IP Core User Guide

ALTIOBUF Bidirectional Buffer

The bidirectional buffer essentially combines the input buffer and the output buffer, incorporating the input path, output path, and oe path.

By combining the input and output buffers, the output path and oe path are placed before the buffer and the input path is placed after the buffer.

Figure 7. Internal Architecture of ALTIOBUF (Bidirectional Buffer Mode)

By following these specifications, only the input path needs a register external to the IP core. The output and oe registers that are added externally to the IP core are optional.

Figure 8.  ALTIOBUF (Bidirectional Buffer Mode) Connected with External FlipflopsThis figure shows an example of the ALTIOBUF IP core (bidirectional buffer mode) when output, oe, and input path registers are used that are external to the IP core.

The external register placement is similar to the input/output buffers, where the output and oe registers drive the datain and oe ports of the ALTIOBUF IP core (bidirectional buffer mode) and the dataout port drives the input register.

Note:
  • The dynamic termination control path also contains output delay chain 1 and output delay chain 2, which are not accessible through the ALTIOBUF IP core (bidirectional buffer mode). When both the oe and dynamic termination control are used, the two signals (oe and dynamic termination control) can be out of synchronization.
  • It is not recommended to switch these two signals simultaneously.
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