Reset Controller Interface Peripheral

RSTC (AT91S_RSTC) 0xFFFFFD00 (AT91C_BASE_RSTC)

RSTC Software API (AT91S_RSTC)

Offset Field Description
0x0RSTC_RCR (SYSC_RCR)Reset Control Register
0x4RSTC_RSR (SYSC_RSR)Reset Status Register
0x8RSTC_RMR (SYSC_RMR)Reset Mode Register

RSTC Register Description

RSTC: AT91_REG SYSC_RCR - Reset Control Register

Offset Name Description
0SYSC_PROCRST
AT91C_SYSC_PROCRST
Processor Reset
0 = No effect.
1 = If KEY is correct, resets the processor.
1SYSC_ICERST
AT91C_SYSC_ICERST
ICE Interface Reset
0 = No effect.
1 = If KEY is correct, resets the processor's ICE Interface.
2SYSC_PERRST
AT91C_SYSC_PERRST
Peripheral Reset
0 = No effect.
1 = If KEY is correct, resets the peripherals.
3SYSC_EXTRST
AT91C_SYSC_EXTRST
External Reset
0 = No effect.
1 = If KEY is correct, asserts the NRST pin.
31..24SYSC_KEY
AT91C_SYSC_KEY
Password
Should be written at value 0xA5. Writting any other value in this field aborts the write operation.

RSTC: AT91_REG SYSC_RSR - Reset Status Register

Offset Name Description
0SYSC_URSTS
AT91C_SYSC_URSTS
User Reset Status
0 = No high-to-low edge on NRST happened since the last read of SYSC_RSR.
1 = At least one high-to-low transition of NRST has been detected since the last read of SYSC_RSR.
1SYSC_BODSTS
AT91C_SYSC_BODSTS
Brown-out Detection Status
0 = No brown-out high-to-low transition happened since the last read of SYSC_RSR.
1 = A brown-out high-to-low transition has been detected since the last read of SYSC_RSR.
10..8SYSC_RSTTYP
AT91C_SYSC_RSTTYP
Reset Type
Reports the cause of the last processor reset.
ValueLabelDescription
0SYSC_RSTTYP_POWERUP
AT91C_SYSC_RSTTYP_POWERUP

Power-up Reset. VDDCORE rising.
2SYSC_RSTTYP_WATCHDOG
AT91C_SYSC_RSTTYP_WATCHDOG

Watchdog Reset. Watchdog overflow occured.
3SYSC_RSTTYP_SOFTWARE
AT91C_SYSC_RSTTYP_SOFTWARE

Software Reset. Processor reset required by the software.
4SYSC_RSTTYP_USER
AT91C_SYSC_RSTTYP_USER

User Reset. NRST pin detected low.
5SYSC_RSTTYP_BROWNOUT
AT91C_SYSC_RSTTYP_BROWNOUT

Brown-out Reset.
16SYSC_NRSTL
AT91C_SYSC_NRSTL
NRST pin level
Registers the NRST level.
17SYSC_SRCMP
AT91C_SYSC_SRCMP
Software Reset Command in Progress.
0 = No software command is being performed. The reset controller is ready for a software command.
1 = A software reset command is being performed by the reset controller, the reset controller is busy.

RSTC: AT91_REG SYSC_RMR - Reset Mode Register

Offset Name Description
0SYSC_URSTEN
AT91C_SYSC_URSTEN
User Reset Enable
0 = The detection of a low level on the pin NRST does not generate a User Reset.
1 = The detection of a low level on the pin NRST does not generate a User Reset.
4SYSC_URSTIEN
AT91C_SYSC_URSTIEN
User Reset Interrupt Enable
0 = USRTS bit in SYSC_RSR at 1 has no effect on SCIRQ.
1 = USRTS bit in SYSC_RSR at 1 asserts SCIRQ.
11..8SYSC_ERSTL
AT91C_SYSC_ERSTL
User Reset Enable
The external reset is asserted during a time of 2 power (ERSTL+1). This allows assertion duration to be programmed between 60us and 2s.
16SYSC_BODIEN
AT91C_SYSC_BODIEN
Brown-out Detection Interrupt Enable
0 = BODSTS at 1 in RSTC_SR has no effect on rstc_irq. 1 = BODSTS at 1 in RSTC_SR asserts rstc_irq.
31..24SYSC_KEY
AT91C_SYSC_KEY
Password
Should be written at value 0xA5. Writting any other value in this field aborts the write operation.