MK64FN1M0VLL12 External RAM interface

[rajeshlakshman]

Hi All,

We have designed on prototype using K64 series controller MK64FN1M0VLL12. Now we have problem with 256KB RAM. we required more trhan this. Can anybody inform whether external RAM interface is possible for this controller , and How ? .Thanks in advance for your help

[xiangjun_rong]

Hi, Rajesh,

Of course, the MK64FN1M0VLL12 has FlexBus module and corresponding FlexBus pin which enable you use External SRAM to extend the internal SRAM. I think the application note an4393 is helpful to understand the FlexBus interface.

Pls download an4393 from the website;

http://cache.freescale.com/files/microcontrollers/doc/app_note/AN4393.pdf?fsrch=1&sr=1&pageNum=1

For the address bus, if the address bus pins is multiplexed with data pins, the latch for example 74LS573 is needed to latch the address in address cycle of FlexBus. pay attention to the address bus connection, if the external SRAM is 16 bits data width and support byte operation, you should connect the A1 of FlexBus to the A0 of SRAM...., while you should connect the corresponding FB_BE_xx to select the byte. If you use 8 bits width SRAM, it is okay to connect the A0 of FlexBus to A0 of SRAM.

If you still have question, pls give the SRAM part number so that we have a target.

BR

Xiangjun Rong