请教:
我们当前的C6678 DDR应用出了点问题,可能与刷新率有关。故最近研究了一下DDR的刷新模式。发现在自刷新模式下,刷新率的调节会更灵活一些。
但是另一方面手册里似乎提到,自刷新模式似乎是一种"low power"的模式。因而我想请问一下,如果把DDR配置成自刷新,是否还能正常访问DDR?访问的带宽和效率是不是会受到影响呢?谢谢!
Brighton Feng:
你说的是"self-refresh"吧? DDR user guide里有说明呀:
The DDR3 memory controller supports self-refresh mode for low power. The controller maintains DDRCKE low to maintain the self-refresh state. In self-refresh, the memory maintains valid data while consuming a minimal amount of power.
The DDR3 memory controller completes all pending memory accesses and refreshes before it puts SDRAM into self-refresh. If a request for a memory access is received, the DDR3 memory controller services the memory access request then returns to the self-refresh state upon completion.
Self-refresh模式下还可以访问,性能当然会受影响。