can these be used to store floating point numbers between resets?

easily save integers but haven't discovered how to stash fp...

digging a bit I see that the gen purpose registers are uint_32 which i think means 32-bit integer only what needs to happen then (i think) is converting a fp number to uint_32 on storage and back again when I pop the register.

can anyone confirm that i'm on the right track? each register is 4 bytes so should be sufficient to hold an fp number (right?)

would not mind some pointers on effecting that...

Hi Gary,

I think you'd want to do something like:

#include "mbed.h"

void set_float(float value) {
    LPC_RTC->GPREG0 = *((uint32_t*)&value);
}

float get_float() {
    return *((float*)&(LPC_RTC->GPREG0));
}

int main() {
    set_float(2.0);
    float v = get_float();
}

You can read set_float from right to left as get the address of the float value (&value), cast that to be an address of an int value (uint32_t*), and then read the value of the int at that address (*). So instead of casting the value itself (which would do a conversion), you cast a pointer to it.

...assuming i haven't made a mistake!

Simon

Simon,

TNX! works a charm. Still learning how the compiler manipulates memory (as you can tell...). One last pesky question then. How to expand this to utilize all of the registers gpreg0-4 ?

gmb