Datasheet

Figure 23-6. Raising the VDDIO Power Supply
Zero-Power Power-On
Reset Cell output
22 - 42 kHz Slow RC
Oscillator output
Fast RC
Oscillator output
Backup Power Supply
vr_on
bodcore_in
vddcore_nreset
NRST
(no ext. drive assumed)
proc_nreset
Note: After “proc_nreset” rising, the core starts fetching instructions from Flash.
periph_nreset
7 x Slow Clock Cycles
3 x Slow Clock
Cyc
les
2 x Slow Clock
Cycles
6.5 x Slow Clock
Cycles
TON Voltage
Regulator
Zero-Power POR
Core Power Supply
RSTC.ERSTL
(5 for sta
rtup slow RC + 2 for synchro.)
default = 2
23.4.7 Core Reset
The Supply Controller manages the vddcore_nreset signal to the Reset Controller, as described in the "Backup
Power Supply Reset" section. The vddcore_nreset signal is normally asserted before shutting down the core power
supply and released as soon as the core power supply is correctly regulated.
There are two additional sources which can be programmed to activate vddcore_nreset:
• a supply monitor detection
• a brownout detection
23.4.7.1 Supply Monitor Reset
The supply monitor is capable of generating a reset of the system. This is enabled by setting
SUPC_SMMR.SMRSTEN.
If SUPC_SMMR.SMRSTEN is set and if a supply monitor detection occurs, the vddcore_nreset signal is immediately
activated for a minimum of one slow clock cycle.
23.4.7.2 Brownout Detector Reset
The brownout detector provides the bodcore_in signal to the SUPC. This signal indicates that the voltage regulation
is operating as programmed. If this signal is lost for longer than 1 slow clock period while the voltage regulator is
enabled, the SUPC asserts vddcore_nreset if SUPC_MR.BODRSTEN is written to ‘1’.
If SUPC_MR.BODRSTEN is set and the voltage regulation is lost (output voltage of the regulator too low), the
vddcore_nreset signal is asserted for a minimum of one slow clock cycle and then released if bodcore_in has been
reactivated. SUPC_SR.BODRSTS indicates the source of the last reset.
Until bodcore_in is deactivated, the vddcore_nreset signal remains active.
SAM E70/S70/V70/V71 Family
Supply Controller (SUPC)
© 2019 Microchip T
echnology Inc.
Datasheet
DS60001527D-page 159