8051 development board in India

No I didn't know. I thought gcc was limited to 16 bit and over processors. That is compiles with the AVR is cool.

Ian

If you want an "int" to be 16 bits, it does help if there are a few 16-bit instructions and/or registers available. [There's also a pretty decent GCC port for the 68HC11 (which, in my book is an 8-bit processor.]

One thing gcc can't handle is when pointers to different types of objects need to be different lengths.

Definitely.

Mine too. Used it not long after it came out.

I assume the paramter passing on the stack model still holds irrespective of processor type? I thought this was one (of many) reasons why 8 bitters were not even considered let alone supported by gcc.

Ian

Sure. For architectures with a decent number of registers, the first one or two parameters are often passed in registers. But, in general gcc expects to be able to use a stack for parameters and local "auto" storage.

Plenty of 8-bit processors (starting at least as early as the mid-70s with the 8080 and 6800 families) had fully functional stacks that could be used for parameter passing. Judging by what I've seen with the 6811 port, just about any of the 8 bit CPUs that have a 16-bit address space with a 16-bit SP and

Processors with variable sized pointers and without a user-accessible, full-sized stack pointer (e.g. 8051) are a problem.

Thanks a lot for the info. I have added that link to my ever increasing 8051 links collection.

really cool link I must say!!

regards, Seemanta

This is fine for microprocessors but potentialy problematic for microcontrollers which have very limited resources e.g. RAM such as the

Ian

Sure. If you don't have a stack, porting GCC is going to be a problem. But -- there's nothing inherently unsupportable about

I have written programs in C compiled with gcc for AVR with 2K code space and 128bytes of ram. I had less ram space problems with this setup than with IAR 8051 compiler and a 8051 clone with the same amount of ram.

Regards Anton Erasmus

Yup. having just a few more registers can save a lot in RAM requirements for stack space. The AVR instruction set was also designed more for compiler use than the 8051 was.