I´m designing a board with a MPC8265, and at this moment I have to define the memory architecture. I have reviewed some reference designs of Freescale and I have seen that in all of them the memory used is a SDRAM. The price is not a problem in my case, so in this way I have two questions:
1.-¿Is better to use an asyncrhronous SRAM instead of an SDRAM? SRAM is faster and simpler to use, ¿is ok? Is more expenxisve, but the price is not a problem in this case; it has to be a secure system, so the price is not important.
2.-In other designs that I know, I have seen taht they use a static RAM for 'program memory' and a NVRAM (FRAM) for 'data memory'. I don´t know in fact whats the purpose of those NVRAM. ¿Whats the purpose for using NVRAM?
Taking into account that this is a secure design for a railway system, I would be very grateful if anyone adviced me choosing the best memory architecture. The program will not be very large, so I think with more or less 512KByte is enough for RAM memory.
Thnaks a lot in advance!!