AT91SAM9G46B-CU View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

AT91SAM9G46B-CU

SMART ARM-based Embedded MPU

Atmel Corporation 

11.4.4.2 Wake-up Reset

The Wake-up Reset occurs when the Main Supply is down. When the Main Supply POR output is active, all the

reset signals are asserted except backup_nreset. When the Main Supply powers up, the POR output is

resynchronized on Slow Clock. The processor clock is then re-enabled during three Slow Clock cycles, depending

on the requirements of the ARM processor.

At the end of this delay, the processor and other reset signals rise. The field RSTTYP in RSTC_SR is updated to

report a Wake-up Reset.

The “nrst_out” remains asserted for EXTERNAL_RESET_LENGTH cycles. As RSTC_MR is backed up, the

programmed number of cycles is applicable.

When the Main Supply is detected falling, the reset signals are immediately asserted. This transition is

synchronous with the output of the Main Supply POR.

Figure 11-5. Wake-up State

SLCK

MCK

Any

Freq.

Main Supply

POR output

backup_nreset

proc_nreset

RSTTYP

periph_nreset

Resynch.

2 cycles

Processor Startup

= 3 cycles

XXX

0x1 = WakeUp Reset

XXX

NRST

(nrst_out)

EXTERNAL RESET LENGTH

= 4 cycles (ERSTL = 1)

SAM9G46 Series [DATASHEET]

77

Atmel-11028G-ATARM-SAM9G46-Datasheet_08-Dec-15

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