Hello everyone, this article and the remaining two articles will explain the market, challenges, case studies, and points to consider when considering specifications for the MIPI interface that we would like you to know when designing.
I will explain it in 3 parts below, so please take care of it.
・Part 1: MIPI interface market and issues, IC types ←This article!
・Part 2: MIPI interface example summary using FPGA
・Part 3: Points to consider when considering MIPI interface specifications on FPGA ・Summary of frequently asked questions
MIPI is an abbreviation for Mobile Industry Processor Interface, and is a standard established in 2005 by the standardization body MIPI Alliance. (MIPI Newcomer Blog #1)
MIPI is a differential high-speed communication that uses low voltage and low power consumption like LVDS, and is characterized by its short transmission distance of about 30 cm and noise immunity.
It is an interface that is mainly used in camera-related products, and is also in demand for consumer devices such as smartphones, industrial devices, and recently, in-vehicle devices.
In this article, we will explain the MIPI interface market, challenges, and IC types.
[What you can learn from this article]
・What kind of market and what kind of issues are there?
・Types of ICs that can implement the MIPI interface
[Recommended for people like this]
・Those who are considering MIPI interface
・Those who are studying the MIPI standard and want to know what kind of IC can realize it.
【table of contents】
・ In what markets is the MIPI interface used? What is your problem?
・ What type of Bridge IC is used to achieve MIPI interface conversion?
In what markets is the MIPI interface used? What is your problem?
Without further ado, I will explain what kind of market the MIPI interface is used in, as well as the current issues and needs.
The MIPI interface was originally used to transmit images/videos for consumer devices. Gradually, it spread to industrial equipment, and now it is also spreading to in-vehicle equipment.
market |
product |
Usage |
consumer equipment 1 |
smartphonedigital camera |
Interface conversion(MIPI to LVDS) |
consumer equipment 2 |
head mounted display |
Video split(HDMI to MIPI 2ch) |
industrial equipment |
machine vision |
Transfer to high-speed communication(MIPI toCoaXpress) |
In-vehicle equipment |
In-vehicle camera surroundview system |
Signal Multiplexing/Aggregation(MIPI Aggregation) |
Here's a refresher on the physical and protocol layers. The MIPI standard has several different physical layers called PHYs.
In this article, we will focus on D-PHY, which is most commonly used in consumer/industrial/in-vehicle equipment.
The protocol layer of MIPI D-PHY has a protocol called DSI/CSI-2.
Although it is just one example, DSI is used around displays to output images and videos from the main IC,
It is often used for display purposes, and CSI-2 is used around cameras,
It is often used in applications where the main IC such as CPU/MCU/SoC receives the MIPI output from the CMOS sensor.
So far, in what markets is the MIPI interface used? To understand the MIPI interface
It was just a quick overview of the physical/protocol layers required.
So what are the challenges when dealing with MIPI interfaces?
This time, 4 “common challenges” when dealing with MIPI interfaces Introducing.
・ The main IC such as CPU does not support MIPI, so it cannot be connected to the CMOS sensor.
・It is necessary to convert the video signal output by MIPI to the display I/F.
・I want to convert the MIPI output from the CMOS sensor to a faster interface.
・I want to divide/integrate MIPI signals from displays and COMS sensors according to the application.
Common issues/needs, such as those above, are provided as examples. Other cases are scheduled to be published as an article in the next case collection.
Please wait until the release.
In any case, what they have in common is that they require interface conversion and require a Bridge IC.
What types of Bridge ICs are there? What are the advantages and disadvantages?
What kind of Bridge IC can realize MIPI interface conversion?
There are two main ways to implement MIPI interface conversion. ASSPs and FPGAs.
I've summarized the pros and cons of each in a table, so I'll explain based on that.
ASSPs |
FPGA |
|
Mounted circuit/function |
Specific function only |
Programmable |
package choices |
Few |
many |
MOQ |
many |
Few |
Design and verification man-hours |
unnecessary |
need |
Regarding implementation circuits and functions, when using ASSP, only integrated functions can be realized,
When using FPGA, functions other than MIPI can be implemented depending on the capacity. (data pre-processing, FIFO, etc.)
Regarding packages, when using ASSP, there are few options because vendors provide standard packages.
On the other hand, when using FPGA, package size and pin pitch can be selected from a wide lineup.
Regarding MOQ, FPGAs can be provided in relatively small quantities.
However, for design and verification man-hours, it is unnecessary when using ASSP,
When using FPGA, it is necessary to design in Verilog/VHDL hardware language, which takes a lot of man-hours.
ASSP and FPGA have advantages and disadvantages, so it is necessary to use them properly according to the situation.
In the next article, how are ASSP and FPGA used along with actual cases? I will explain.
Based on many examples, I would like to share with everyone in what cases FPGA is suitable.
See you next time.
Author: Ishigaki
New Engineer's Struggle ~MIPI Standard Version~
The MIPI standard is a communication standard often used in recent years for display interfaces and image sensor output interfaces.
I know the name of the standard, but what is the communication band? What protocol are you using? Such
Among MIPI, this article focuses on DSI/CSI for newcomers to study from scratch.
We are creating articles about the MIPI standard with the motto of making it easier to understand and more fun than other articles.
Would you like to study with a newcomer?