XE8805 SEMTECH [Semtech Corporation], XE8805 Datasheet - Page 39

• Manufacturer Part Number: XE8805
• Description: Data Acquisition MCU
• Manufacturer: SEMTECH [Semtech Corporation]

6.5 Reset source description
6.5.1
The power on reset (POR) monitors the external supply voltage. It activates a reset on a rising edge of this supply
voltage. The reset is inactivated only if the internal voltage regulator has started up. No precise voltage level
detection is performed by the POR block.
6.5.2
The reset can be activated by applying a high input state on the RESET pin.
6.5.3
A reset signal can be generated by Port A. See the description of the Port A for further information.
6.5.4
The Watchdog will generate a reset if the
watchdog is not cleared in time by the processor. See chapter 6.7 describing the watchdog for further information.
6.5.5
The address space is assigned as shown in the register map of the product. If the
RegSysCtrl register is set and a non-existant address is accessed by the software, a reset is generated.
6.5.6
Entering the sleep mode will reset a part of the circuit. The reset is used to configure the circuit for correct wake-up
after the sleep mode. If the SleepEn bit in the RegSysCtrl register has been set, the sleep mode can be entered
by setting the bit Sleep in RegSysReset. During the sleep mode, the resetsleep signal is active. For detailed
information on the sleep mode, see the system documentation.
6.6 Control register description and operation
Two registers are dedicated for reset status and control, RegSysReset and RegSysCtrl. The bits Sleep, and
SleepEn are also located in those registers and are described in the chapter dedicated to the different operating
modes of the circuit (system block).
The RegSysReset register gives information on the source which generated the last reset. It can be read at the
beginning of the application program to detect if the circuit is recovering from an error or exception condition, or if
the circuit is starting up normally.
The last bit concerns the sleep mode control (see system documentation for the sleep mode description).
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• when ResBusError is 1, a forbidden address access generated the reset.
• when ResWD is 1, the watchdog generated the reset.
• when ResPortA is 1, a PortA combination generated the reset.
• when ResPad is 1, a reset pin generated the reset.
• when ResPadSleep is 1, a reset pin in sleep mode generated the reset.
Note: If no bit is set to 1, the reset source was the internal POR.
Note: Several bits might be set or not, if the register was not cleared in between 2 reset occurrences. Write
any value in RegSysReset to clear it.
Note: When a reset pin wakes up the chip from the sleep mode, ResPad and ResPadSleep bits are equal
at 1.
Power On Reset
RESET pin
Programmable Port A input combination
Watchdog reset
BusError reset
Sleep mode
EnResetWD
6-4
bit in the RegSysCtrl register has been set and if the
EnBusError
XE8805/05A
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bit in the