This is the week of meritorious service

这是一个不到2000行的操作系统，巧妙地利用ARM9 CPU的内存管理单元(MMU)实现进程的切换。ARM9的4G虚拟地址可分成128个进程空间，每个32M。虽然它们的虚拟地址(VA)都是0-(32M-1)，但是对应的MVA(Modified vitual address,由虚拟地址VA和进程号PID组合而来)不一样，设置MVA对应的页表指向不同物理地址就可以很方便地让各进程运行空间相互隔开。代码很少，注释丰富，希望能对想理解操作系统、了解ARM体系结构的朋友有所帮助。 -This is a trip of less than 2000 operating system, cleverly using ARM9 CPU memory management unit (MMU) to achieve the switching process. ARM9 4G virtual address can be divided into 128 process space, each 32M. While their virtual address (VA) are 0- (32M-1), but the corresponding MVA (Modified Virtual address, and by the virtual address VA and the process of portfolio from PID) not the same, set MVA corresponding page table at the different physical address can be very easy to let the the process of separating the mutual operation of space. Code rarely Notes rich, in hopes of understanding the operating system, understanding the ARM architecture friends help.

ARM 嵌入式系统 LPC22xx UART1实验代码-ARM Embedded System LPC22xx UART1 experimental code

his project was built and tested with WinAVR-20060125. Make sure the MCU target define in the Makefiles corresponds to the AVR you are using!! To build the code, just install WinAVR and run "make" from the console in echomaster and echoslave subdirs. "make program" will program the device if you have a AVRISP attached. Remember to set the AVR device to at least 8MHz. The AVR may use the programmable clock from MC1319x, just remember to check if the MC1319x and SPI communication is working FIRST! Otherwise you wont get any clock signal to the AVR and then you can t program it or reset the fuses! The MC1319x has default clock output of 32kHz so you will have to set your programmer to a very low frequency (

f2812 内部ad 调试成功 f2812 内部ad 调试成功-f2812-house ad debug debugging success f2812 internal ad success

基于优龙ST2410开发板的原代码,包括各种驱动程序-Long ST2410 distinctions based development board"s original code, including driver

smdk2440 usb driver-smdk2440 usb driver

实现一个简单的电话簿程序,具有添加,删除,查询电话号码的功能-To achieve a simple phone book program has to add, delete, check functional telephone number

W90X900 Stand-alone Library(Non OS Library) Audio function library

学习单片机C语言，12864点阵型液晶显示-MCU learning C language, 12864 points, formation LCD

飞利浦公司uCOS-II_LPC2000.移植源代码-Philips uCOS-II_LPC2000. Transplant source code