Code Example For Stop2 Mode ?

[m2s]

Hy, I'm wondering if someone have an example on how they save all register value into ram and get them back into the register when returning from Stop2 mode.

Is theyre a faster way than simply copy the information regsiter by regsiter ?

best regards.

[Ake]

The fastest way for saving the registers would be something like this

pshh ;save h 2

pshx ;save x 2

psha ;save a 2

tpa ;get a copy of the status register 1

psha; and save it 2

tsx; get stack pointer to hx 2

sthx savedSP ;save the stack pointer 4

So it would take 2+2+2+1+2+2+4 = 15 clock cycles or 0.75 uS on a 20 Mhz 9S08.

In the savedSP word the SP should be saved so when the CPU is powered up, it first checks the savedSP word. If it is < 0xffff, the saved data can be restored. If = 0xffff, no data has been saved.

Regards,

Ake

[m2s]

Thank's

To that I need to add the instructions to save all I/O regsiter to.