atmel 89c51

specialized in technology based on RISC chip design and development companies, as intellectual property suppliers, not directly engaged in wafer production, by Transfer design license by the company to produce the unique chip, the world's major semiconductor manufacturers (RFID RF Express Note: such as Philips, TI, Intel , BroadCom, Atmel, etc.) from arm company to buy its design arm microprocessor core, according to their different application field

cycle, slave pulls down SDA, sends an ACK NACK: in the 9th CLK cycle, Slave keeps SDA high, sending a NACK one time can transmit multiple bytes until master sends start/ Stop If the slave device is too late to process data, it can keep the SCL low, forcing master to enter the wait state. I2C Master Sample code (GPIO simulation) can refer to: STM32 under the simulation I2C C language implementation I2C slave Example I2C slave implementation should be more difficult than I2C master, the implement

Device Controller (UDC)-driven implementations supported by the kernel, as well as the implementation of frameworks and different gadget. Take AT91 ARM9 As an example, the bottom driver is at91_udc.c (for the SOC that supports high Speed USB 2.0 is ATMEL_USBA_UDC.C), it implements the unified interface defined by Gadget.h, and then various gadget on the upper layer Driver (such as SERIAL.C, etc.) call this set of unified interface to achieve different types of functions, such as USB serial, u d

)-driven implementations supported by the kernel, as well as the implementation of frameworks and different gadget. Take AT91 ARM9 As an example, the bottom driver is at91_udc.c (for the SOC that supports high Speed USB 2.0 is ATMEL_USBA_UDC.C), it implements the unified interface defined by Gadget.h, and then various gadget on the upper layer Driver (such as SERIAL.C, etc.) call this set of unified interface to achieve different types of functions, such as USB serial, u disk, USB ethernet and s

, USB ethernet and so on. The Atmel USB port frame diagram: Configure kernel configure with the following command Supportgadget serial 1 Copy kernel Configure file to the obj directory in the current directory 2 Configuring the Configure file under the obj directory 3 Save the configured configure file as a. config 4 copy. config file to the CONIFG directory of Linux kernel Make Mtxxxx_smp_mod_dbg_defconfig arch=arm o=obj/mtxxxx_smp_mod_dbg_defconf