MS51系列芯片SPROM怎么使用

只看该作者 · 2021-9-22 18:41

从新唐官网下载MS51 KEIL的例程解压包里有SPROM的程序，用KEIL打开编译没有问题，KEIL设置是这样的：

连接上仿真器运行程序，在MAIN主循环里调用SPROM函数后，没有退出SPROM函数，继续运行MAIN后面的代码，而是从SPROM函数里跳到了STARTUP.A51的启动代码，程序复位了。一直这样循环。搞不懂怎么用这个SPROM安全保护存储器，有小伙伴用过这个SPROM吗？是不是KEIL的设置方法不对？

只看该作者 · 2021-9-23 09:19

sprom加密跟没加密都可以跑代码
(1) SPROM non-secured mode (the last byte is 0xFF). The access behavior of SPROM is the same
with APROM and LDROM. All area can be read by CPU or ISP command, user can be erased and
programmed by ISP command.

(2) SPROM secured mode (the last byte is not 0xFF). In order to conceal SPROM code in secured
mode, CPU only can perform instruction fetch and get data from SPROM when CPU is run at SPROM
area. Otherwise, CPU will get all 00H for data access. In order to protect SPROM, the CPU instruction
fetch will also get zero value when ICE (OCD) port is connected in secured code. At this mode,
SPROM doesn’t support ISP program, read or erase.