Intel 386 - Manual (Page 195)

Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL
8-14
None
Syntax:
int error;
WORD psclk = 0x02;
error = Set_Prescale_Value(psclk);
Real/Protected Mode:
No changes required.
******************************************************************************/
int Set_Prescale_Value(WORD Prescale)
{
WORD clkprs = 0x0000;
clkprs = _GetEXRegWord(CLKPRS);
/* clear lowest nine bits of clkprs */
clkprs = clkprs & 0xfe00;
/* check that prescale value is only 9 bits in length */
if (Prescale != (Prescale & 0x01ff))
return(E_BADVECTOR);
_SetEXRegWord(CLKPRS, (clkprs | Prescale));
return(E_OK);
}/*Set_Prescale_Value*/
/******************************************************************************
Enter_Idle_Mode:
Description:
This function programs the 386EX for Idle mode. This freezes the
core clocks while leaving the peripheral clocks toggling.
Parameters:
None
Returns:
None
Assumptions:
None
Syntax:
Enter_Idle_Mode();
Real/Protected Mode: