基于SST39VF640x闪存的擦写器设计

Design of Programmer Based on SST39VF640x Flash Memory

为了实现对SST39VF640x闪存4M空间的字编程,需要搭建一个16位的数据通道,使得C51微处理器每次对外存的访问,都能以双字节的方式进行,同时,须补齐系统指令寻址能力的短板,以满足对4M地址的I/O操作需求。实施中,充分利用C51外总线固有时序,并引入一定数量的寄存器,预设或锁存地址和数据,在读/写周期内,借助/RD、/WR和ALE的协调,完成总线信息的归并及拆分。通过总线接口的再构造,使本质上属于字节操作的微系统具有了字传输能力,并对擦/写流程进行简化,提出了具体实施方案,大幅缩短了试验周期,加快了试验进程。

In order to achieve SST39VF640 x flash 4M word programming space, we need to build a 16-bit data path so that the microprocessor C51 performs double-byte manner in each external memory access. The system shall be filled with instruction addressing capability to meet demands for4 M address I/O operations. During implementation, it fully uses external bus C51 inherent timing, and introduces a number of registers, the default or latched address and data, read/write cycle,coordinating aid/RD,/WR and ALE to complete the bus information merger and split. Though the reconstruction of bus interface, the micro-system belonging to byte operations in nature has the word transmission capacity. It simplifies the erase/write process, makes specific embodiments, substantially shortens the test period and speeds up the test process.