HDMI Intel® FPGA IP User Guide

ID 683798
Date 3/07/2025
Public
Document Table of Contents

6.1.21. Avalon Memory-Mapped Demultiplexer

Avalon memory-mapped demultiplexer demultiplexes a single Avalon host interface to four Avalon agent interfaces for HDMI register, Clocked Video to AXI4-stream, EDID RAM and HDCP-based on the respective address offset. The host on the Avalon memory-mapped demultiplexer uses word addressing.

Master Address Offset Size

(double-word)

Description
EDID RAM 0x0000 16 For HDMI DDC channel for accessing external sink SCDC and EDID and for link training function
Clocked Video to AXI4-stream 0x0100 256 Control and status register on Clocked Video to AXI4-stream
EDID RAM access 0x0200 1 Indicates host processor is accessing or updating EDID RAM. All other read and write operations to the EDID stop. Upon de-assertion of this signal, RX hotplug signal toggles to trigger the external HDMI source to read the EDID.
HDCP register 0x0300 256 Reserved for HDCP registers
HDMI register 0x0400 256 Control and status register on HDMI core

The output data from the Avalon memory-mapped demultiplexer (AVMM demultiplexer) to HDMI register, clocked video to AXI4-stream bridge, and HDCP are 32 bits. The write and read operation are channeled through to the respective master according to the address offset. However, EDID RAM has only 8 bits interface due to limitation that the same interface is used by the I2C target for DDC. Hence, 1 single write operation from the AVMM demultiplexer agent interface of 32-bits data translates into 4 continuous write operation to the EDID RAM with the address increased accordingly on the EDID RAM.