ATA6020N ATMEL Corporation, ATA6020N Datasheet - Page 19

• Manufacturer Part Number: ATA6020N
• Description: Low-current Microcontroller For Watchdog Function
• Manufacturer: ATMEL Corporation

4.5
4708D–4BMCU–09/05
Power-down Modes
Table 4-7.
Note:
The sleep mode is a shut-down condition which is used to reduce the average system power
consumption in applications where the microcontroller is not fully utilized. In this mode, the sys-
tem clock is stopped. The sleep mode is entered via the SLEEP instruction. This instruction sets
the interrupt enable 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 microcontroller exits the sleep mode by carrying out any interrupt or a reset.
The sleep mode can only be kept when none of the interrupt pending or active register bits are
set. The application of the $AUTOSLEEP routine ensures the correct function of the sleep
mode.
The total power consumption is directly proportional to the active time of the microcontroller. For
a rough estimation of the expected average system current consumption, the following formula
should be used:
I
I
The ATA6020N 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 pro-
grammable if the clock for the on-chip peripherals is active or stopped during the sleep mode. If
the clock for the core and the peripherals is stopped the selected oscillator is switched off.
Table 4-8.
Note:
total
DD
Mode
Power-down
depends on V
(V
1
2
SLEEP
Active
Mode
DD
If bit CCS = 0 in the CM-register, the RC-oscillator 1 always stops.
1. Osc-Stop = SLEEP and NSTOP and WDL
,f
syscl
OS1
) = I
1
0
Oscillator Select
Power-down Modes
DD
Sleep
CPU Core
SLEEP
SLEEP
and f
RUN
OS0
+ (I
1
1
syscl
DD
t
Osc-Stop
active
Input for SUBCL
YES
NO
NO
/t
total
C
C
in
in
)
/16
/16
(1)
Brown-out
Function
Active
Active
STOP
Selected Oscillators
RC-oscillator 1 and external input clock
RC-oscillator 1 and RC-oscillator 2
RC-oscillator 1
RC-oscillator 2
STOP
RUN
RUN
ATA6020N
External Input
Clock
STOP
YES
YES
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