spi bus speed

receiving buffer immediately. set the full flag (BF) and interrupt flag (sspif) of the master receiving buffer to "1 ". After the master CPU detects the full or interrupt mark position 1 of the master receiving buffer, it can read the data in the receiving buffer. Similarly, after the CPU detects that the receiving buffer is full or the interrupt flag is 1, the data in the receiving buffer can be read to complete the communication process. Here, dspic30f6014 is set as the master controller, and

!/*****************************************************************************************************/The code for the SPI Universal Interface layer is concentrated in:/drivers/spi/spi.c.Initialization of the SPI device model Typically, depending on how the Linux device model is organized, various devices are hung on the appropriate

SPI, is the abbreviation of English serial Peripheral interface, as the name implies is the serial peripheral device interface. SPI, is a high-speed, full-duplex, synchronous communication bus, and on the chip's pin only occupies four lines, saving the chip pin, while the layout of the PCB space saving, convenient, it

About I2C and SPI bus protocols Iicvs SPI Currently, in the low-end digital communication application field, we can see IIC (Inter-Integrated Circuit) and SPI (serial peripheral interface) everywhere. The reason is that these two communication protocols are very suitable for close-range and low-

= Src_clk_nr;pd.cfg_gpio = (cfg_gpio)? Cfg_gpio:s3c64xx_spi0_cfg_gpio; ... s3c_set_platdata (PD, sizeof (PD), s3c64xx_device_spi0);}The above functions mainly specify the GPIO configuration used by the controller, the number of pin pins and the clock configuration. This information is to be used in the controller driver behind.Register the SPI Controller Platform_driver In the previous section, we registered the

; ...... Pd.num_cs = Num_cs; PD.SRC_CLK_NR = SRC_CLK_NR; Pd.cfg_gpio = (cfg_gpio)? Cfg_gpio:s3c64xx_spi0_cfg_gpio; ...... S3c_set_platdata (PD, sizeof (PD), s3c64xx_device_spi0); The above function is to specify the GPIO configuration that the controller uses, the number of slices of pins and the clock configuration. This information is used in the subsequent controller driver. registering the platform_driver of the SPI Controller I

The last 2 weeks have been debugging IIC and SPI bus equipment, here record 2 kinds of bus, in case of forgetting. One IIC Bus The abbreviation of I2c--inter-ic serial Bus is the serial transmission bus between chips introduced by

MCU simulation SPI interface-deep understanding of SPI bus protocol SPI (serial peripheral interfacer serial peripheral interface) is a synchronous serial communication interface launched by Motorola, the serial connection between the microprocessor compaction controller and the peripheral extended chip has developed i

I still remember that the first time I used the SPI device was my junior summer vacation. At that time, I bought a wireless module with my teammates and used a single-chip microcomputer for wireless transmission, but the code was not written by myself, although this function was implemented, I still had no idea about SPI at the time. Senior, I felt ashamed to ask how to use

pending spi_message structures under Master, and the worker thread will process each of these message requests on a first-in, one-out basis, after each message transfer is complete, corresponding to the Spi_ The complete callback function of the message structure is called to notify the Protocol driver to prepare the next frame of data. This is the spi_message of the queue. When a worker thread wakes up, the relationship between Spi_master, Spi_message, and spi_transfer can be used to describe:

below it, and the worker threads will process the message requests one at a time according to the FIFO principle, and after each message transfer, the corresponding SPI_ The complete callback function of the message structure is invoked to notify the Protocol driver of preparing the next frame of data. This is the queue of spi_message. When a worker thread wakes up, the relationship between Spi_master, Spi_message, and Spi_transfer can be described in the following illustration: queues and

U8 spi1_readwritebyte (U8 txdata) {U8 retry=0; while (Spi_i2s_getflagstatus (SPI1, spi_i2s_flag_txe) = = RESET)//Check the specified SPI labelLog bit set or not: Send cache null flag bit {retry++; if (retry>200) return 0; } spi_i2s_senddata (SPI1, TxData); Send a data retry=0 via peripheral Spix; while (Spi_i2s_getflagstatus (SPI1, spi_i2s_flag_rxne) = = RESET)//Check the specified SPI flag bit setti

SPI, I²C, serial port, I believe if you are engaged in embedded development, will be used to the three communication protocols, serial port words because and baud rate related, so the general CPU or MCU will only be equipped with two or three serial port, and the transmission of data, the SPI and i²c use will be more, A blog was found below. Turn around, 1, the UART is two lines, one sends a r

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 spee