ds2251 Maxim Integrated Products, Inc., ds2251 Datasheet
ds2251
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ds2251 Summary of contents
Page 1
... This allows frequent software upgrades, adaptive programs, customized systems, etc. In addition, by using NV RAM, the DS2251T is ideal for data logging applications. The powerful real time clock includes interrupts for time stamp and date. It keeps time to one-hundredth of seconds using its onboard 32 kHz crystal ...
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... The DS2251T provides the benefits of NV RAM without using I/O resources. Between 32 kbytes and 128 kbytes of onboard NV RAM are available. A non-multiplexed Byte-wide address and data bus is used for memory access. This bus, which is available at the connector, can perform all memory access and also provide decoded chip enables for off-board memory mapped peripherals ...
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... DS2251(T) BLOCK DIAGRAM Figure DS2251T ...
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... V CC P2.2 41 BA0 P2.3 42 BA1 P2.4 43 BA2 P2.5 44 BA3 P2.6 45 BA4 P2.7 46 BA5 47 BA6 PSEN ALE 48 BA7 49 BA8 PROG P0.7 50 BA9 P0.6 51 BA10 P0.5 52 BA11 P0.4 53 BA12 P0.3 54 BA13 DESCRIPTION DS2251T 55 INTB 56 BD0 57 BD1 58 BD2 59 BD3 60 BD4 61 BD5 62 BD6 63 BD7 PE3 67 PE4 68 INTP 69 INTA 70 SQW 71 VRST 72 BA15 ...
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... If connected to ground, the micro will enter Bootstrap loading on power-up. This signal is pulled up internally. DESCRIPTION and . These are on 16k boundaries, so BA14 or BA15 PE3 PE4 W is not lithium backed and can be connected to any PE3 is not lithium backed and can be connected to any PE4 DS2251T . BA13-0 connect directly to ...
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... Secure Microcontroller Data Book. MEMORY ORGANIZATION Figure 2 illustrates the memory map accessed by the DS2251T. The entire 64k of program and 64k of data are available to the Byte-wide bus. This preserves the I/O ports for application use. The user controls the portion of memory that is actually mapped to the Byte-wide bus by selecting the Program Range and Data Range ...
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... DS2251T MEMORY MAP IN NON-PARTITIONABLE MODE (PM=1) Figure 2 DS2251T MEMORY MAP IN PARTITIONABLE MODE (PM=0) Figure DS2251T ...
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... The User’s Guide has more information on this PF topic. The trip points V and V CCMIN respectively. When V drops below the DS2251T invokes a reset state. No further code CCMIN signal will be driven to a logic 0. V VRST drops further to below V CC are listed in the electrical specifications. PFW ...
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... CC I IDLE I STOP 0.5V) CC =0V and V =0V. In this state =0˚C to70˚ TYP MAX UNITS + 0.15 0.45 V 0.15 0.45 V 4.8 V 4.8 V -50 A -500 150 k 4 4.37 4.50 V 4. DS2251T 10%) NOTES ...
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... CLK 0 2t -70 CLK 8 -150 CLK 8t -90 CLK 9t -165 CLK 9t -105 CLK 3t -50 3t +50 CLK CLK 4t -130 CLK t -60 CLK 7t -150 CLK DS2251T NOTES 5 1 10%) UNITS MHz ...
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... PARAMETER 25 Data Valid after High WR 26 Low to Address Float High to ALE High RD WR EXPANDED PROGRAM MEMORY READ CYCLE SYMBOL @ 16 MHz WRHDV t RDLAZ t t RDHALH DS2251T MIN MAX UNITS -90 ns CLK -50 ns CLK 0 ns -40 t +50 ns CLK CLK ...
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... EXPANDED DATA MEMORY READ CYCLE EXPANDED DATA MEMORY WRITE CYCLE DS2251T ...
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... MHz t CLKF @ 16 MHz SYMBOL to 3. CSU t POR =0˚C to70˚ MIN MAX =0˚C to70˚ MIN MAX 130 (note 6) 21504 DS2251T 10%) UNITS 10%) UNITS s t CLK ...
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... Clock Rising Edge to Input Data Valid 39 Input Data Hold after Rising Clock Edge (t =0˚C to70˚ SYMBOL MIN t 12t SPCLK CLK t 10t -133 DOCH CLK t 2t -117 CHDO CLK t CHDV t 0 CHDIV DS2251T =5V 10%) CC MAX UNITS 10t -133 ns CLK ns ...
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... CEHDV t Active W AVRWL t RWLDV t 3-4 High PE CEHDV t High W RWHDV t Low Time) RWLPW =0˚C to70˚ MIN MAX 4t -35 CLK 4t -30 CLK 4t -35 CLK 1t +40 CLK 10 3t -35 CLK 20 1t -15 CLK 0 6t -20 CLK DS2251T 10%) UNITS ...
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... MIN 160 RDZ (t =0˚C to70˚ SYMBOL MIN 130 DS2251T =5V 10%) CC MAX UNITS 130 ns 130 =5V 10%) CC MAX UNITS ...
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... Low to Active PROG 70 High to Inactive PROG (t SYMBOL t ACC t CAC t ACD t CRQ (t PROG SYMBOL t PRA t PRI =0˚C to70˚ MIN MAX 130 110 =0˚C to70˚ MIN MAX 48 48 DS2251T 10%) UNITS 10%) UNITS CLKS CLKS ...
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... The user should check with the crystal vendor for a worst case specification on this time. 7. pin operation is specified with RST = 3.0V. BAT CLKR . SS ; XTAL2 not CC = 25°C. DS2251T , CLKR = 10 CLKF ...
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... PACKAGE DRAWING PKG INCHES DIM MIN MAX A 4.245 4.255 B 3.979 3.989 C 0.995 1.005 D 0.395 0.405 E 0.245 0.255 F 0.050 BSC G 0.075 0.085 H 0.245 0.255 I 1.750 BSC J 0.120 0.130 K 2.120 2.130 L 2.245 2.255 M 0.057 0.067 N - 0.275 O - 0.145 P 0.047 0.054 DS2251T ...
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... Correct Absolute Maximum Ratings to reflect changes to DS5001FP microprocessor. 2. Add note clarifying that SRAM contents are not defined under storage temperature conditions. The following represent the key differences between 11/08/99 and 01/18/00 version of the DS2251T data sheet. Please review this summary carefully. 1. Document converted from interleaf to Microsoft Word. ...