MC68HC05X16 Datasheet, PDF (32/232 Pages) Freescale Semiconductor, Inc – High-density complementary metal oxide semiconductor HCMOS) microcontroller unit

Freescale Semiconductor, Inc.
The following list summarizes the effect of WAIT mode on the modules of the MC68HC05X16.
2
– The watchdog timer functions according to the mask option selected; see
Section 10.1.4.2
– The EEPROM is not affected; see Section 3.7
– The SCI is not affected; see Section 7.14
– The timer is not affected; see Section 6.7
– The PLM is not affected; see Section 8.4
– The A/D converter is not affected; see Section 9.4
– The I-bit in the CCR is cleared
– The MCAN module is unaffected
2.2.2.1 Power consumption during WAIT mode
Power consumption during WAIT mode depends on how many systems are active. The power
consumption will be highest when all the systems (A/D, timer, EEPROM, SCI and MCAN) are
active, and lowest when the EEPROM erase and programming mechanism, SCI and A/D are
disabled and the MCAN is in SLEEP mode. The timer cannot be disabled in WAIT mode. It is
important that before entering WAIT mode, the programmer sets the relevant control bits for the
individual modules to reflect the desired functionality during WAIT mode.
Power consumption may be further reduced by the use of SLOW mode. (See Section 2.2.3).
2.2.3 SLOW mode
The SLOW mode function is controlled by the SM bit in the miscellaneous register at location
$000C. It allows the user to insert, under software control, an extra divide-by-16 between the
oscillator and the internal clock driver (see Figure 2-5). This feature allows all the internal
operations to slow down and thus reduces power consumption.
Warning: The SLOW mode function should not be enabled while using the A/D converter or while
erasing/programming the EEPROM unless the internal A/D RC oscillator is turned on.
MODES OF OPERATION AND PIN DESCRIPTIONS MC68HC05X16
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