DS2252T(2000) View Datasheet(PDF) - Dallas Semiconductor -> Maxim Integrated
Part Name
Description
Manufacturer
DS2252T Datasheet PDF : 15 Pages
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DS2252T MEMORY MAP WITH (PES=1) Figure 4
PROGRAM MEMORY
FFFFh --
DATA MEMORY (MOVX)
-- 64K
DS2252T
C000h --
PARTITION
B000h --
4000h --
NV RAM
PROGRAM
0000h --
REAL-TIME
CLOCK
-- 16K
= NOT ACCESSIBLE
POWER MANAGEMENT
The DS2252T monitors VCC to provide Power-fail Reset, early warning Power-fail Interrupt, and switch-
over to lithium backup. It uses an internal band-gap reference in determining the switch points. These are
called VPFW, VCCMIN, and VLI respectively. When VCC drops below VPFW, the DS2252T will perform an
interrupt vector to location 2Bh if the power-fail warning is enabled. Full processor operation continues
regardless. When power falls further to VCCMIN, the DS2252T invokes a reset state. No further code
execution will be performed unless power rises back above VCCMIN. All decoded chip enables and the
R/ W signal go to an inactive (logic 1) state. VCC is still the power source at this time. When VCC drops
further to below VLI, internal circuitry will switch to the built-in lithium cell for power. The majority of
internal circuits will be disabled and the remaining nonvolatile states will be retained. The User’s Guide
has more information on this topic. The trip points VCCMIN and VPFW are listed in the electrical
specifications.
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