Using two hardware images (one at a time)

[Altera_Forum]

Hello, 

 We want to configure our on-board Startix FPGA (1S60) with one of the two different hardware images on run-time (power-on). That is, depending on our selection, a 'select' line will choose which hardware image should configure FPGA. At a time only one of the two hardware image would configure FPGA.  So we thought of using two EPC16 devices, storing different hardware images on them, and muxing their data outputs. The 'select' line will then choose what hadware image should configure the FPGA.  (1) Muxing data ports seems all right, but what abt DCLK and other signals?  (2) When we are selecting one of two hardware images, FPGA should be given some signal so that it reloads the .pof file from one of the two devices. How do we ensure that?  (3) I read Altera Configuration documents but didn't find any scheme for this purpose. Is there other note which details out the configuration scheme of two different hardware images on run-time.  Sincerely,

[Altera_Forum]

I have implemented such a feature what we call factory (save) image and user image. during power up the user image ist loaded and upon request or if the user image is unloadable the factory is loaded as a fallback solution. 

 implementing such a feature with 2 epcs is possible i have done that.  but if you calculate the price for 2 epcs and compare it with 1 maxII and a cfi flash that is needed for nios :-) then you will end up with the maxii solution. the maxii here does all the update handling that is needed to take care of 2 images. an EPM240T100 with a cheap 16Bit CFI Flash is the cheapest solution for this. Now nios can boot from one image to another and vice versa at any time. if an update if the user image fails and leads to an unuseable image the design will automatically fallback to the second image. this image loader is faster than epcs !  this works great here !  but i can not hand out any code. but it is very easy to implement this.  maybe some cyclone III will support this .. altera it is your task to implement this :-) to get rid of an external comfiguration device and use dedicated pins for a parallel cfi image WITH 2 images for safe fall back. hope someone from altera reads this :-)  Regards  Michael Schmitt