10 Sep
2006
10 Sep
'06
9:11 p.m.
Alexey Toptygin wrote:
I was reading the C language spec (C99) and I got to wondring: are/were
there C implementations that had no stack, or a rising stack? There's a
falling stack in every implementation I've seen, but the spec doesn't
require it.
Most machines that did not have a stack, like a PDP-8 or other larger
machines from that era never did have that problem since C was never
ported to them to my knowlege. Cross compilers to new-ish micro-controlers
may have limitations is the only examples I can think of.
The only machine with a rising stack that I know of was a 18 bit CPLD computer
design I was planning to build with 4 registers - sp,ac,pc,ix.
+offset+<sp:0000>, -offset+<sp:sp>.
Since I am now planning to build a 12/24 bit cpu, I can use a real register
for global-static variables. I am taking a RISC idea of a 0 constant register
for abs static variables.
Alexey