电子图书《华中理工大学出的C51教材》，很不错的。

P89V51RD2系列芯片是具有串口下载功能（ISP）和在KEIL中进行调试的功能（SOFTICE）。 新的芯片是ISP功能，通过FlashMagic 软件可以设置其为SOFTICE功能。 但要想回到ISP功能，则没有现成的好办法，只有通过编程器了。 但现在可以通过这个程序来恢复其ISP功能（禁止SOFTICE）。-P89V51RD2 series with the serial port chip is the ability to download (ISP) and the KEIL for debugging feature (SOFTICE). The new chip is the ISP, through FlashMagic software can be set to SOFTICE its function. However, to return to the ISP, there is no ready-made good, and that only through a programmer. But now through this procedure to restore its ISP (Prohibition SOFTICE).

AVR单片机的电机测速程序，利用ICCAVR编译，通过ICP测出电机的转速并通过数码管显示和串口上传-AVR MCU electrical velocimetry procedures, take advantage of ICCAVR compiled by ICP measured motor speed and through a digital display and serial From

这是用单片机实现的多功能数字钟,通过8255扩展端口,AD0809将模拟信号转换成数字信号进行处理,可以比较精确的测出电压值.-This is the MCU multifunction digital clock, through the 8255 expansion port, AD0809 a conversion of analog signals into digital signal processing, more precise measuring the voltage values.

插在usb上使用的声卡的原理图,器件少,简单实用

基于AD9850/9851的数字信号发生器,调试通过，keilC51环境-AD9850/9851 based on digital signal generator, debug through, keilC51 environment

这是一个实现单片机串口通讯的简单例子,对初学者是很有用的-This is a microcontroller serial communication to achieve a simple example

简单的单片机LED，用串口调试来实现其LED的显示。数码管的显示-Simple single-chip LED, using serial debugging to achieve its LED display. Digital tube display

12864中文字库测试程序 ST7920-12864 Chinese font ST7920 test procedure

MP3基于AVR的源程序，包含文件系统以及SD卡的驱动程序，并且有音频解码程序-AVR based MP3 source code, including file system, as well as SD card driver, and there are audio decoding process

jlink的FLASH参数配置工具，自动生成CSV格式的文件，用于自己添加新的FLASH型号。-jlink the FLASH parameter configuration tool that automatically generates CSV format file, add a new FLASH for its own models.