Such as the accuracy of frequency measurement based on the principle of design,...

TLC549是一种采用8位逐次逼近式工作的A/D转换器。内部包含系统时钟、采样和保持、8位A/D转换器、数据寄存器以及控制逻辑电路。TLC549每25uS重复一次“输入―转换―输出”。器件有两个控制输入：I/O CLOCK和片选（CS）。 内部系统时钟和I/O CLOCK可独立使用。应用电路的设计只需利用I/O时钟启动转换或读出转换结果。当CS为高电平时，DATA OUT处于高阻态且I/O时钟被禁止。 -TLC549 is a used 8-bit successive approximation type of work the A/D converter. Contains the internal system clock, sample and maintain, an 8-bit A/D converter, data register and control logic circuit. TLC549 each repeat 25uS

51的键盘扫描程序,与原来的扫描方式不同,这种方式可以处理多键同时按下.-51 keyboard scanning procedures, with the original scan different ways, this approach can handle multi-button pressed together.

x5045的应用程序，多初学的朋友很有帮助！-X5045 applications, and more helpful beginner

C8051控制器操作SD卡实现文件系统，兼容FAT16,FAT32-C8051 controller operation SD card file system compatible with FAT16, FAT32

AD转换的分辨率=参考电压/(总元素-1) 当AD为8位，总元素=256（ff）取参考电压=Vdd=5V时 分辨率=5/(256-1)= 0.019607843-resolution of the AD converter reference voltage =/(total element 1) When the AD for eight, with a total element = 256 (ff) the reference voltage Vdd = = = 5V resolution 5/(256-1) = 0.019607843

C51_Keyboard_Examples

OPENGMAX，大家可能都用到过，这里可以和大家分享一些优化的代码，可以共同提高，ARMcode 优化-OPENGMAX, you may have used before, here we can share some optimized code, can work together to improve, ARMcode optimization

IAR中S3C44B0X 示例程序，IAR中S3C44B0X 可以通过该模板进行开发-IAR in S3C44B0X sample procedures, IAR in S3C44B0X can be developed through the template

一种基于高速逻辑器件（触发器，计数器和门电路等）控制的，可与各种单片机系统友好连接的高速A/D转换采集系统。-Based on high-speed logic device (flip-flops, counters and gates, etc.) control can be friendly with a variety of single-chip microcomputer system to connect high-speed A/D conversion acquisition system.

用单片机控制74LS244做的串口通信系统。-74LS244 done with single-chip microcomputer to control the serial communication system.