connecting Nios ii system and other system over ram-controller with different clocks?

[Altera_Forum]

hello, 

 i plan a new project and i found a problem right at the beginning. the plan is to connect an external computer over the gpio as adress- and databus to an fpga-board and use the board to do some calculations and then the external computer can access to the result. so, I want to do the calculation with a nios ii system and have a little space in memory, where the external computer can place and get data for/from the nios ii. the problem is, that the nios ii can run at 100 MHz, but the external system run's on a much slower clock. how can I connect this two systems?  maybe I only need a push in the right direction :-)  best regards, peabrain

[Altera_Forum]

You could create a shared memory: instantiate a dual port ram with port 1 connected to Nios data bus, while port 2 is exposed to the external system which must drive the data/address/control lines according to the avalon specifications. 

Then you should provide some sort of software handshaking for data transfer.