DS5002FP_1 Datasheet, PDF (5/29 Pages) Dallas Semiconductor – Secure Microprocessor Chip

DS5002FP
SRAM. CE3 is lithium-backed and will remain at a logic high when V_CC falls below V_LI.
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CE4 - Chip Enable 4. This chip enable is provided to access a fourth 32k block of memory. It connects to
the chip enable input of one SRAM. When MSEL=0, this signal is unused. CE4 is lithium-backed and
will remain at a logic high when V_CC falls below V_LI.
78
PE1 - Peripheral Enable 1. Accesses data memory between addresses 0000h and 3FFFh when the PES bit
is set to a logic 1. Commonly used to chip enable a byte-wide real time clock such as the DS1283. PE1 is
lithium-backed and will remain at a logic high when V_CC falls below V_LI. Connect PE1 to battery-backed
functions only.
3
PE2 - Peripheral Enable 2. Accesses data memory between addresses 4000h and 7FFFh when the PES bit
is set to a logic 1. PE2 is lithium-backed and will remain at a logic high when V_CC falls below V_LI.
Connect PE2 to battery-backed functions only.
22
PE3 - Peripheral Enable 3. Accesses data memory between addresses 8000h and BFFFh when the PES bit
is set to a logic 1. PE3 is not lithium-backed and can be connected to any type of peripheral function. If
connected to a battery-backed chip, it will need additional circuitry to maintain the chip enable in an
inactive state when V_CC < V_LI.
23
PE4 - Peripheral Enable 4. Accesses data memory between addresses C000h and FFFFh when the PES bit
is set to a logic 1. PE4 is not lithium-backed and can be connected to any type of peripheral function. If
connected to a battery-backed chip, it will need additional circuitry to maintain the chip enable in an
inactive state when V_CC < V_LI.
32
PROG - Invokes the Bootstrap Loader on a falling edge. This signal should be debounced so that only
one edge is detected. If connected to ground, the micro will enter Bootstrap loading on power-up. This
signal is pulled up internally.
42
VRST - This I/O pin (open drain with internal pullup) indicates that the power supply (V_CC) has fallen
below the V_CCmin level and the micro is in a reset state. When this occurs, the DS5002FP will drive this
pin to a logic 0. Because the micro is lithium-backed, this signal is guaranteed even when V_CC =0V.
Because it is an I/O pin, it will also force a reset if pulled low externally. This allows multiple parts to
synchronize their power-down resets.
43
PF - This output goes to a logic 0 to indicate that the micro has switched to lithium backup. This
corresponds to V_CC < V_LI. Because the micro is lithium-backed, this signal is guaranteed even when V_CC
=0V. The normal application of this signal is to control lithium powered current to isolate battery-backed
functions from non-battery-backed functions.
14
MSEL - Memory select. This signal controls the memory size selection. When MSEL= +5V, the
DS5002FP expects to use 32k x 8 SRAMs. When MSEL = 0V, the DS5002FP expects to use a 128k x 8
SRAM. MSEL must be connected regardless of partition, mode, etc.
53
SDI – Self-Destruct Input. An active high on this pin causes an unlock procedure. This results in the
destruction of Vector RAM, Encryption Keys, and the loss of power from V_CCO. This pin should be
grounded if not used.
72
CE1N - This is a non-battery-backed version of CE1 . It is not generally useful since the DS5002FP can
not be used with EPROM due to its encryption.
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NC - Do not connect.
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