The I2C architecture consists of three components:
(1) I2C Core
(2) I2C bus driver
(3) I2C Device Driver
I2C core: Provides the registration and cancellation methods for I2C bus drivers and device drivers, the upper layer of the
1. I2C ProtocolTwo two-way serial lines, one data line SDA, and one clock line SCL.The data transmitted by SDA is transmitted at a large end. Each transmission is 8 bits, that is, one byte.Multimastering is supported, and only one master can be created at any time point.Each device on the bus has its own ADDR, a total of 7 bits, and the broadcast address is all 0.The system may have multiple chips of the same type. For this reason, ADDR is divided int
After discussing the initialization and deletion of drivers for I2C devices and I2C adapters, we will focus on several function operations in file_operations, paste the file_operations struct code first. Let's see which functions are included.
Static const struct file_operations i2cdev_fops ={
The structure must be quite clear. Therefore, the I2C Driver provide
Since the use of computers and networks, it has greatly changed our world. So far, the intelligent brain of chips and hardware devices has been applied and developed in more and more fields. As for protocol, there are also many changes. Next we will introduce the I2C bus protocol for audio and video devices.
I2C bus Definition
The I2C (Inter-Integrated Circuit) b
What is wiki )?
First, we need to clarify that the inventor of the Wiki concept is Ward cunnhan. What does the word wiki mean? According to the FAQ, the word wikiwiki comes from wee Kee in Hawaii, which originally meant "quick. In fact, wiki is simple and fast. You can see that w
I2C bus principle and application example
The I2C (Inter-Integrated Circuit) bus is a two-line serial bus developed by Philips to connect the microcontroller and its peripheral devices. The I2C bus was originally developed for audio and video devices in 1980s and is now mainly used in server management, including communication in the status of a
After completing the Platform_device addition, the I2C subsystem will perform the Platform_driver registration process.
Platform_driver registration by calling the initialization function I2c_adapter_s3c_init letter
Number to complete.
The I2c_adap_s3c_init () function body is as follows:
static int __init i2c_adap_s3c_init (void)
{return
platform_driver_register (s3c24xx_i2c_driver);
}Platform_driver_register (s3c24xx_i2c_driver), will complete the
1. Communication Interface
The data sent or received by I2C is encapsulated by the packet struct i2c_msg.
Struct i2c_msg {_ 2010addr; // slave address _ 2010flags; // flag # define i2c_m_ten 0x0010 // ten address flag # define i2c_m_rd 0x0001 // receives the data flag _ Len; // Data Length _ u8 * Buf; // Data Pointer };
ADDR indicates the slave address, flags indicates the communication, 0 indicates the sent data, and i2c_m_rd indicates the received d
ack and nack of I2C signal
We usually in debugging I2C may rarely pay attention to the nack signal, only know if the master send data, MSB first, LSB after sending a byte (8 bit), then Slave will reply to an ACK signal, but sometimes I2C Slave may send a nack signal, let's take a look at the nack signal.
1, from the spec under a paragraph:
2. Translation:
E
at24c02d
at24c02d because it is not a standard I2C bus, the I2C 8-byte address bus select、read is not fully used, but the 5+3 external pin setting (A2,A1,A0) is used to determine which device to communicate with, and a I2C bus can mount up to 8 at24c02d, just 2 three times.
Do not understand why at24c02d I2C inside the
A cssp specification-visual enhancement engine chip produced by quick logic is used to enhance the image data output to the Panel. Schematic:
Generally, you only need to add an I2C device and write it to the register group during initialization. Linux I2C architecture:I2C core i2c-core.c: Provides I2C bus drivers and
I2C bus signal timing Summary
Idle bus statusThe SDA and SCL signal lines of the I2C bus are in the idle state at the same time.At this time, the output-level FET of each device is in the cutoff state, that is, the bus is released.By the two signal lines of the respective pull-up resistance to raise the level.
Start SignalThe SDA level of the data line is lowered (that is, the negative hop) during the hig
Address: http://blog.csdn.net/coder_jack/article/details/6419903
Send a start and stop command consecutively for the following test:
1. Send the start command to address an existing device, receive the ACK, and then send the Stop command. Everything is normal and the Stop waveform is displayed.
2. Send the start command to address a non-existing slave device. If no response is received, send the Stop command to release the bus and the waveform of the bus release cannot be seen. Only the check re
Principles, differences and Applications of SPI, I2C, and UART Serial Bus
1. UART is a two-line interface. One transmission and one receiving interface can communicate with each other in full duplex mode, and the number of lines is relatively small. Data is transmitted asynchronously, with strict timing requirements on both parties, and the communication speed is not fast. It is used most frequently for multi-host communication.2. Compared
During Android development and transplantation, you sometimes need to read and write a device, but the system may not provide the corresponding services. We need to develop our own hardware access service to control devices. The following example is the process of reading and writing the most simple I2C device EEPROM, I2C driver writing there are two ways, one is to use the
1.OV PWDN is a high level of effective, that is, high electricity peacetime camera sleep, at this time I2C also do not work (with i2cdetect detection), in low electricity peacetime camera work;
2.i2cdetect is a very good tool, you use this work, do not care about the device's register address and data bit width, as long as the device to ensure the operating voltage and its mount to which a I2C controller, y
The premise is that the driver of the I2C controller must have been running normally, the standard I2C tool can only read and write to 8-bit address, but the EEPROM of this 16-bit address will be powerless
So this kind of 16-bit address for read and write support, in the embedded domain is still very common
The main use of standard Linux I2C interface, struct i2c
Differences:
SPI: high-speed synchronous serial port. 3 ~ 4-line interface, independent and synchronous sending and receiving
UART: Universal asynchronous serial port. Bidirectional communication based on the standard baud rate is slow
I2C: A three-line serial transmission mode. The communication protocol and usage can be found on the Internet.
Bidirectional data transmission with three linesSerial peripheral interfaceUART: Universal asynchronous tra
Analysis of the current situation and trend of Wiki Development in China
With the rapid development of the Internet, the Collaborative Design and parallel engineering (concurrent engineering) in the field of computer aided design (CAD), which was widely used within enterprises at the end of the 20th century) the concept is applied to websites, allowing Internet users to participate in content collection, editing, and transmission. In recent years, thi
The following is a detailed analysis of how to write the first part: the I2C driver of the master chip is divided into two steps: Write the bus driver: select a master chip, for example: (self-compiled chip) the I2C support for this chip (bus driver support) is not found in Driver/I2C/busses/i2c-s3c2410.c )... (Unlucky
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