t6020m ATMEL Corporation, t6020m Datasheet - Page 18

• Manufacturer Part Number: t6020m
• Description: Low-current Microcontroller For Watchdog Function
• Manufacturer: ATMEL Corporation

2.6
The sleep mode is a shut-down condition which is used to
reduce the average system power consumption in applica-
tions where the C is not fully utilized. In this mode, the
system clock is stopped. The sleep mode is entered via the
SLEEP instruction. This instruction sets the interrupt en-
able bit (I) in the condition code register to enable all
interrupts and stops the core. During the sleep mode the
peripheral modules remain active and are able to generate
interrupts. The C exits the sleep mode by carrying out
any interrupt or a reset.
The sleep mode can only be kept when none of the inter-
rupt pending or active register bits are set. The application
of the $AUTOSLEEP routine ensures the correct function
of the sleep mode.
Table 5 Power-down modes
* Osc-Stop = SLEEP & NSTOP & WDL
T6020M
18 (54)
Power-down
SLEEP
Active
Mode
Power-down Modes
CPU Core
SLEEP
SLEEP
RUN
Osc-Stop*
YES
NO
NO
Brown-out
Function
Active
Active
STOP
The total power consumption is directly proportional to
the active time of the C. For a rough estimation of the
expected average system current consumption, the fol-
lowing formula should be used:
I
The T6020M has various power-down modes. During the
sleep mode the clock for the MARC4 core is stopped.
With the NSTOP-bit in the clock management register
(CM) it is programmable if the clock for the on–chip pe-
ripherals is active or stopped during the sleep mode. If the
clock for the core and the peripherals is stopped the se-
lected oscillator is switched off.
DD
depends on V
I
total
(V
RC-Oscillator 1
RC-Oscillator 2
DD
,f
DD
STOP
syscl
RUN
RUN
and f
) = I
syscl
Sleep
.
+ (I
Rev. A3, 02-Apr-01
DD
External Input
Clock
STOP
YES
YES
t
active
/ t
total
)