Mark Butcher

Coldfire code size compared to ARM in thumb mode

Discussion created by Mark Butcher on May 7, 2006
Latest reply on May 8, 2006 by Dennis Shutt
Hi All
I am wondering about the code size of the Coldfire family compared to the code size for ARM in thumb mode.
I noticed that when porting a project from the HCS12 to the Coldfire its size increased by almost a factor of 2. I assume that this is quite normal due to the fact that each instruction requires a long word rather than a short word.
The same project ported to an ARM processor in thumb mode did not increase in size dramarically - that is why the thumb mode exists (small code size with slight reduction of speed).
Are there any methods of improving the code efficiency of the Coldfire?
I am thinking about the M5223X devices with 128k or 256k FLASH since it seems to mean that a project requiring 64k on the HCS12 will require approx. 128k on the Coldfire and so the larger memory doesn't automatically result in larger application possibilities.
Are these points valid or is there some method of titling the situation when using the Coldfire?
Many thanks for any remarks.
Mark Butcher