8-bit MicrocontrollersのトピックRe: MC9S08LC60: Why is stop mode being reset?

MC9S08LC60: Why is stop mode being reset?

MotownSide — Mon, 21 Dec 2009 11:06:15 GMT

Hi,

We are unable to get into any stop mode. The current is always high ~4mA. It seems that when we enter stop mode, it is immediately being reset. We are interested in getting into stop3 mode.

We followed the settings in the datasheet. (Table 3.1)

Below is the settings we set for stop3 mode

SOPT1_STOPE=1;

SPMSC1_LVDSE=0;

SPMSC1_LVDE=0;

SPMSC2_PDC=1;

Is there something else that we overlooked?

Re: MC9S08LC60: Why is stop mode being reset?

bigmac — Mon, 21 Dec 2009 11:22:44 GMT

Hello, and welcome to the forum.

Have you allowed that the SOPT1 register is "write once"? This means that all bits of the register, including the STOPE bit, must be simultaneously written, usually early in the initialisation process. It is not possibly to set bits individually, and if this is what you are attempting, it may mean that the STOP instruction is never enabled, resulting in an illegal opcode reset when you attempt to enter stop mode.

Regards,

Mac