Migrating Code from C5x to C28x -- DSP Processors

I am not familiar with the C5x, this is what I found while porting code from a +/- conventional micro (80196) to the 2812:

(a) Memory requirements:

(a.1) The C2000 family access memory as 16 bit words only, a C "char" is 16 bit. Code that has lots of char variables to store logic values, small counters, etc. will require more memory than what would be the case on a machine addressing 8-bit units.

(a.2) To use the full addressing range of the CPU you need the configure the compilers to use 22 bit addresses, (two words), affecting both memory size and performance.

(b) Performance: The 2812's 150 MIPS figure can be achieved only for code running from internal RAM and without too many branches that would starve the internal prefetch/pipelining logic. Actual average performance will be much lower (10 to 50 MIPS?)

(c) Debugging aids:

(c.1) TI's Code Composer's Studio offers a lot of functionality to "see" inside a running system. The catch: to provide this functionality it uses available/unused CPU time and targetdebugging system bandwidth. If your project really maxes-out the CPU, the debugging becomes much more difficult.

(c.2) Never got more than one breakpoint to work reliably. (Used JTAG emulators from Spectrum-Digital, GAO and BlackHawk.) Makes difficult debugging multi-tasking + ISR applications.

(d) FLASH cycle limits: The internal FLASH has a much lower program cycles limit than regular FLASH chips.

Roberto Waltman