摘要
介绍SI-PROG编程器的工作原理,利用PC机串口UART芯片实现单片机的ISP下载。PC机串口8250芯片中SOUT,DTR,RTS,CTS四个引脚的电平可通过其内部的几个寄存器分别进行控制或读取,利用引脚可实现单片机的ISP下载。介绍了8250与单片机之间通信信号的逻辑关系以及电平转换,分析了接收器的阈值电压的特点,给出了使用SI-PROG编程器的条件。最后,以AVR单片机为例介绍了下载程序设计。结果表明,利用PC机串口UART芯片可以实现对AVR单片机的ISP下载,其硬件电路和软件设计都很简单。
The principle of SI- PROG programmer is introduced, the purpose is using UART chip in PC＇s serial port to realize the ISP download of single chip computer. The level of SOUT,DTR,RTS and CTS pins of the 8250 chip in PC＇s serial port could be controlled or read separately through a few internal registers of 8250, so the ISP programming of single chip computer could be realized by making use of those four pins. In this paper, both the logical relationship and the level translation of communication signals between 8250 and single chip computer are introduced,the characteristics of the receiverrs threshold voltage are analyzed and the condition of using the SI--PROG programmer is provided. In the end,the AVR single chip com- puter is taken as an example to introduce the downloading program design. The result indicates that using UART chip in PC＇s serial port can realize the ISP download of single chip computer. The hardware circuit and software design are both simple.
出处
《现代电子技术》
2009年第8期14-16,21,共4页
Modern Electronics Technique
