Mitsubishi Motors DS5000TK - Manual (Page 3)

USER’S GUIDE
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LARGE NONVOLATILE MEMORY
Soft Microprocessor chips provide nonvolatile memory
control for standard CMOS SRAM. Modules combine
the microprocessor chip with memory and lithium back-
up. This includes conditionally write protected chip en-
ables and a power supply output that switches between
+5V and battery backup. The chip enables are decoded
automatically based on user selectable memory sizes
and partitioning. Partitioning defines the portion of
memory used for program and data segments. Areas
that are designated program are always write protected
and are treated as ROM. Data areas are write protected
only when power is out of tolerance. A large nonvolatile
memory is useful for data logging and as flexible pro-
gram storage. Memory will be retained for over 10 years
at room temperature in the absence of power by ultra
low–leakage lithium backed circuits.
IN–SYSTEM LOADING
The in–system programming capability lets the user up-
date program code at any time. This program loading is
supervised by a built–in ROM–based bootstrap loader.
The ROM loader becomes transparent once program
loading is complete. All devices allow program loading
via the serial port. Data memory can also be retrieved
using this loader function. Selected versions provide
other parallel loading protocols as well. In–system load-
ing allows a system to be configured during final system
test. A user can load custom software, diagnostic rou-
tines, or calibration constants. If something changes or
new features arise, the system can then be repro-
grammed while in the field.
HIGH RELIABILITY OPERATION
Secure Microcontroller devices are designed for unsu-
pervised operation in remote locations. Special fea-
tures prevent a system from running out of control dur-
ing transient events. These include a reset when power
is out of tolerance; an early warning power–fail interrupt
that allows software to save critical data; and a watch-
dog to reset the micro if it gets lost. Also, nonvolatile
memory allows software to save the operating state so a
task can be resumed when power returns to normal.
The Secure Microcontroller family consists of three
chips and their associated modules. Differences stem
from I/O, memory access, and security features. The
DS5000FP is used in DS2250T and DS5000(T) mod-
ules. The DS5001FP is used in the DS2251T, and the
DS5002FP is used in the DS2252T. A full selector guide
with all memory and speed permutations is provided in
the next section.
CHIP DESCRIPTION
BYTE–WIDE BUS
MEMORY ACCESS SECURITY PACKAGE
DS5000FP Soft Microprocessor Chip 8, 32, 64*K bytes Optional 80–pin QFP
DS5001FP 128K Microprocessor Chip 32, 64, 128K bytes None 80–pin QFP
DS5002FP Secure Microprocessor Chip 32, 64, 128K bytes Maximum 80–pin QFP
MODULE DESCRIPTION ON–BOARD MEMORY PACKAGE
DS2250(T) DS5000FP on SIMM 8, 32, 64*K bytes 40–pin SIMM
DS5000(T) DS5000FP in DIP Module 8, 32K bytes 40–pin DIP
DS2251T DS5001FP on SIMM 32, 64, 128K bytes 72–pin SIMM
DS2252T DS5002FP on SIMM 32, 64, 128K bytes 40–pin SIMM
*32K partitionable, 32K restricted to data memory only.
NOTES:
“T” specifies optional on–board real–time clock.
128K byte versions provide fixed 64K program, 64K data segments. Other versions are partitionable.