DS12887A Datasheet, PDF (1/19 Pages) Maxim Integrated Products – Real-Time Clock

DS5000(T)
DS5000(T)
Soft Microcontroller Module
FEATURES
• 8–bit 8051 compatible Microcontroller adapts to task–
at–hand:
– 8 or 32K bytes of nonvolatile RAM for program
and/or data memory storage
– Initial downloading of software in end system
via on–chip serial port
– Capable of modifying its own program and/or
data memory in end use
• Crashproof operation:
– Maintains all nonvolatile resources for 10 years
in the absence of V_CC
– Power–fail reset
– Early warning power–fail interrupt
– Watchdog timer
• Software Security Feature:
– Executes encrypted software to prevent unau-
thorized disclosure
• On–chip, full–duplex serial I/O ports
• Two on–chip timer/event counters
• 32 parallel I/O lines
• Compatible with industry standard 8051 instruction
set and pinout
• Optional Permanently Powered Real–Time Clock
(DS5000T)
PIN ASSIGNMENT
P1.0
1
P1.1 2
P1.2
3
P1.3
4
P1.4
5
P1.5
6
P1.6
7
P1.7
8
RST 9
RXD P3.0 10
TXD P3.1 11
INT0 P3.2
12
INT1 P3.3 13
T0 P3.4
14
T1 P3.5
15
WR P3.6 16
RD P3.7 17
XTAL2 18
XTAL1 19
GND 20
40
V_CC
39
P0.0 AD0
38
P0.1 AD1
37
P0.2 AD2
36
P0.3 AD3
35
P0.4 AD4
34
P0.5 AD5
33
P0.6 AD6
32
P0.7 AD7
31
EA
30
ALE
29
PSEN
28
P2.7 A15
27
P2.6 A14
26
P2.5 A13
25
P2.4 A12
24
P2.3 A11
23
P2.2 A10
22
P2.1 A9
21
P2.0 A8
40–PIN ENCAPSULATED PACKAGE
DESCRIPTION
The DS5000(T) Soft Microcontroller Module is a fully
8051 compatible 8–bit CMOS microcontroller that offers
“softness” in all aspects of its application. This is ac-
complished through the comprehensive use of nonvola-
tile technology to preserve all information in the ab-
sence of system V_CC. The internal program/data
memory space is implemented using either 8K or
32K bytes of nonvolatile CMOS SRAM. Furthermore,
internal data registers and key configuration registers
are also nonvolatile. An optional real time clock gives
permanently powered timekeeping. The clock keeps
time to a hundredth of a second using an on–board
crystal.
021998 1/19