DP84902M NSC [National Semiconductor], DP84902M Datasheet
DP84902M
Related parts for DP84902M
DP84902M Summary of contents
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DP84902 1 7 Encoder Decoder Circuit General Description The DP84902 is designed to perform the encoding and de- coding for disk memory systems It is designed to interface directly with Integrated Read Channel Products (such as National Semiconductor’s DP84910) and ...
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... It inhibits writing and resets the encoder state machine when at a logical low level There are no set-up or hold timing requirements for the enabling or disabling of this input TL F 11963– 2 FIGURE 2 DP84902 Pinout Order Number DP84902M or DP84902MS See NS Package Number M20B or MSA20 Functional Description 10% g ...
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Pin Descriptions (Continued) Symbol Pin Output Pin Descriptions CODEOUT RLL CODE OUTPUT This output issues encoded data MSB first to be written to the disk The control register controls various attributes of this output It can be ...
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DC and AC Device Specifications Absolute Maximum Ratings Note Absolute Maximum Ratings are those values beyond which the safety of the device cannot be guaranteed The device should not be oper- ated at these limits The parametric values defined in ...
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Control Register Operating Conditions otherwise specified Symbol Parameter CRC Pulse Width (positive or negative) (see Figures 4 and PW(CRC) t CRD Setup Time with respect to CRC (positive edge) SU(CRD) (see Figures 4 and ...
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DC Electrical Characteristics fied Symbol Parameter V High Logic Level (Note 2) OH Output Voltage Low Logic Level (Note 2) OL Output Voltage ...
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AC Electrical Characteristics Write Mode unless otherwise specified Symbol Parameter t NRZIO(0 1) Setup Time WCLK SU(NRZIO(0 1)) (positive edge) (see Figures 5 and 8 ) (Note 3) t NRZIO(0 1) Hold Time WCLK ...
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AC Electrical Characteristics Write Mode FIGURE 5 Write Timing Diagram 11963 – 5 ...
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AC Electrical Characteristics Read Mode unless otherwise specified Symbol Parameter t SYNCDATA Setup Time SYNCCLK SU(SYNCDAT) (negative edge) (see Figures 6 and SYNCDATA Hold Time SYNCCLK H(SYNCDAT) (negative edge) (see Figures ...
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AC Electrical Characteristics General otherwise specified Symbol Parameter t ECL Section Turn On Time CRL S pins ECLON (positive edge) (see Figures 6 5 and 7 ) (Note 2) t ECL Section Turn Off Time w r ...
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AC Electrical Characteristics Waveforms FIGURE 7 Propagation Delay Waveforms FIGURE 9 Input or Output Pulse Width Waveforms TL F 11963– 11 FIGURE 8 Setup and Hold Time Waveforms TL F 11963– 13 FIGURE 10 TRI-STATE Output Enable and Disable Waveforms ...
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Functional Description The Encoder Decoder (ENDEC) translates NRZ data to and from the (1 7) RLL format receives and transfers NRZ data in a 2-bit format generates code output that can be made either TTL or ECL compatible indicates the ...
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Functional Description (Continued RLL CODE The (1 7) code used is based on US patent cross-licensing with International Business Machines Cor- poration (IBM ) Table II summarizes the decoding method used for this device Nine SYNCDATA bits are ...
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Functional Description (Continued) TABLE IV Encoding State Table NRZIO CODEOUT M L CURRENT 1 7 OUT S S STATE ...
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... Physical Dimensions inches (millimeters) 20-Pin Small Outline Package Order Number DP84902M NS Package Number M20B 15 ...
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... Italiano National does not assume any responsibility for use of any circuitry described no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications Order Number DP84902MS NS Package Number MSA20 2 A critical component is any component of a life ...