[FRAM71] Pre-Production Batch

[Dave Frederickson]

(12-20-2014 07:15 PM)J-F Garnier Wrote:  

(12-14-2014 12:40 AM)rprosperi Wrote:  Reconfiguring the IRAMs to ROM will protect the port contents from errant code romping thru memory.

Changing the module type from IRAM to ROM without precautions can produce several side effects and strange errors, especially if there are Basic programs inside. The right, secure way to create a ROM module is to use ROMCOPY.
It is also possible to manually compile each Basic program by hand by running each.

I believe we're looking at two different situations here. The first has to do with copying ROM images to a FRAM71 IRAM and the difference between leaving the memory configured as IRAM or reconfiguring it as ROM. The second situation is what you describe which is to create a ROM image. In that case ROMCOPY is the correct method as it creates an image with the proper checksums.

Note the caveat in Note 6 on p.12 of the manual. Soft-configured ROMs should be configured the same as the physical module. So while I'm unaware of any undesired side-affects, that means that a 32K ROM, which is physically two 16K ROMs, should be configured in FRAM71 as two 16K Chips. The image can be copied to a single 32K Chip, however the ROM test in the Diag ROM will fail calculating the checksums.

Dave