ds2251t Maxim Integrated Products, Inc., ds2251t Datasheet - Page 8

• Manufacturer Part Number: ds2251t
• Description: Ds2251t 128k Soft Microcontroller Module
• Manufacturer: Maxim Integrated Products, Inc.

DS2251T
DS2251T MEMORY MAP WITH (PES = 1) Figure 4
POWER MANAGEMENT
The DS2251T monitors V
to provide power-fail reset, early warning power-fail interrupt, and
CC
switchover to lithium backup. It uses an internal band-gap reference in determining the switch points.
These are called V
, V
, and V
, respectively. When V
drops below V
, the DS2251T will
PFW
CCMIN
LI
CC
PFW
perform an interrupt vector to location 2Bh if the power-fail warning is enabled. Full processor operation
continues regardless. When power falls further to V
, the DS2251T invokes a reset state. No further
CCMIN
code execution will be performed unless power rises back above V
. All decoded chip enables and
CCMIN
the R/
signal go to an inactive (logic 1) state. The
signal will be driven to a logic 0. V
is still
W
VRST
CC
the power source at this time. When V
drops further to below V
, internal circuitry will switch to the
CC
LI
built-in lithium cell for power. The majority of internal circuits will be disabled and the remaining
nonvolatile states will be retained.
will be driven to a logic 0. The Secure Microcontroller User’s
PF
Guide has more information on this topic. The trip points V
and V
are listed in the electrical
CCMIN
PFW
specifications.
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