Forum Discussion
Honored ContributorConfig compression makes no difference
I ran my Cyclone 3 design with and without compressed config file
generation & in both cases the .sof file came out to be 350KB. No change with compression. Did I miss some Quartus setting or do I just have an uncompressible design ? How much compression are people seeing ?22 Replies
Altera_Forum*.sof files are never compressed, because compression isn't available for JTAG configuration download. Compression is used for *.rbf, *.pof or e.g. indirect JTAG programming files (*.jic). If you generate files with the programming file conversion tool, compression need to be enabled in the tool, the compression state of the input files doesn't matter.
- Altera_Forum
Thanks for the info. I tried .pof & the size is 512KB, bigger than the original .sof. Then I tried .rbf & the size is 128KB. Terrific but .rbf does not seem compatible with the EPCS4. I'd like to use the EPCS4 for the small size. Any way to use active serial config + compressed file ?
- Altera_Forum
use the Convert Programming Files dialogue to create a .jic file containing the .sof. you will be able to enable compression of the .sof using this tool
- Altera_Forum
The .jic file is also 512KB. No advantage at all. This is a very screwy feature. compression or small flash chip but you can't have both.
- Altera_Forum
you can have both. which device are you using?
- Altera_Forum
The current design is Cyclone 3 using the EPCS4 flash. The next revision
is going to be the Cyclone 4 GX using the EPCS4 flash. If I can't get compression to work, I'll have to move up to the next larger EPCS chip. - Altera_Forum
not family but device
- Altera_Forum
EP4CGX15 device
- Altera_Forum
it looks like that device will fit in an EPC4 without compression, but you could use compression to make some additional space for user data
take a look at the generated .map file before and after compression, you can see the end address change - Altera_Forum
What I want is to fit 2 or more config files in the same flash & change the
starting self load address to point to 1 of the config files. Thus the need to compress & get at least 2 config files into the flash.
