Maxim Integrated Secure Microcontroller - Manual (Page 63)

Secure Microcontroller User’s Guide
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Control/Status Bits for Power Control
PCON.6 POR
Power-On Reset Indicates that the previous reset was initiated during a power-on sequence.
Initialization:
Cleared to 0 by a power-on reset. Remains at 0 until set to a 1 by software.
Read Access: Can be read normally at any time.
Write Access: Can be written only by using the timed-access register .
PCON.5 PFW
Power-Fail Warning Indicates that a potential power-failure is in progress. Set to 1 when V
CC
voltage is
below the V PFW threshold. Cleared to a 0 immediately following a read of the
PCON register. Once set, it remains set until read regardless of V
CC
.
Initialization: Cleared to a 0 during a power-on reset.
Read Access: Can be read normally at any time.
Write Access: Cannot be written.
PCON.3
EPFW
Enable Power-Fail Interrupt Used to enable or disable the power-fail interrupt. When EPFW is set to 1, it is
enabled; it is disabled when EPFW is cleared to a 0.
Initialization: Cleared to a 0 on any type of reset.
Read Access: Can be read normally anytime.
Write Access: Can be written normally anytime.
PCON.1:
STOP
Stop Used to invoke the Stop mode. When set to a 1, program execution will terminate
immediately and Stop mode operation will commence. Cleared to a 0 when
program execution resumes following a hardware reset.
Initialization: Clear to a 0 on any type of reset.
Read Access: Can be read anytime.
Write Access: Can be written only by using the timed-access register.
PCON.0:
IDL
Idle Used to invoke to idle mode. When set at 1, program execution is halted and
resumes when the idle bit is cleared to 0, following an interrupt or a hardware
reset.
Initialization: Cleared to 0 on any type of reset or interrupt.
Read Access: Can be read normally anytime.
Write Access: Can be written normally anytime.
Table 7-A. Pin States in Idle/Stop Modes
MODE
PROGRAM
MEMORY
ALE PSEN P0 P1 P2 P3
Idle Bytewide 1 1 Port Data Port Data Port Data Port Data
Idle Expanded 1 1 High-Z Port Data Address Port Data
Stop Bytewide 1 0 Port Data Port Data Port Data Port Data
Stop Expanded 1 0 High-Z Port Data Port Data Port Data