日志
5509A扩展外部存储器SDRAM时对GPIO0引脚的设置
热度 1 |||
这几天在学习板上扩展SDRAM时，把一个变量通过#pragma DATA_SECTION( );定义到SDRAM里面，编译，下载到5509A里面，在用view memory 查看此变量对应的地址，当把变量名放在地址输入栏，按回车之后，CCS就断开了与板子的连接，并提示如下错误：
Trouble Reading Memory Block at 0x20000 on Page 1 of Length 0x5d: Error 0x80000002/-1144 Fatal Error during: Memory, The memory at 0x00040000 continually indicated it was 'not ready' The emulator was unable to regain control of the processor. The processor must be reset.
Failed to remove the debug state from the target before disconnecting. There may still be breakpoint opcodes embedded in program memory. It is recommended that you reset the emulator before you connect and reload your program before you continue debugging.
地址错误，有问题！
后来再看5509A的data manual 里的引脚介绍，并行总线一栏有如下描述
并行总线是复用的，当GPIO0的电平置高时，复用为EMIF 的地址线。
把GPIO0置高，下载程序，查看变量地址，OK！
