DP8409AN National Semiconductor, DP8409AN Datasheet
DP8409AN
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DP8409AN Summary of contents
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... TRI- STATE Only the bank with its associated RAS low will be written to or read from TRI-STATE is a registered trademark of National Semiconductor Corp PAL is a registered trademark of and used under license with Monolithic Memories Inc C 1995 National Semiconductor Corporation TL F 8409 ...
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... Block and Connection Diagrams Order Number DP8409AD DP8409AN DP8409AN-3 or DP8409AV-2 See NS Package Number D48A N48A or V68A Pin Definitions V GND GND The three supply pins have been assigned to the center of the package to reduce voltage drops both DC and AC There are also two ground ...
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Pin Definitions (Continued) TABLE I DP8409A Mode Select Options (RFSH) Mode ...
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Conditions for All Modes (Continued) DP8409A DRIVING ANY 16k OR 64k DRAMs The DP8409A can drive any 16k or 64k DRAMs All 16k DRAMs are basically the same configuration including the newer 5V-only version Hence in most applications differ- ent ...
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Conditions for All Modes (Continued) When the DP8409A refresh mode the pin indicates that the on-chip refresh counter has reached its end-of-count This end-of-count is selectable as 127 255 or 512 to accommodate 16k ...
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DP8409A Functional Mode Descriptions MODE 1 AUTOMATIC FORCED REFRESH In Mode 1 the R C (RFCK) pin becomes RFCK (refresh cycle clock) instead and CAS remains high If RFCK is kept permanently high then whenever M2 (RFSH) ...
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DP8409A Functional Mode Descriptions MODE 2 AUTOMATIC BURST REFRESH This mode is normally used before and or after a DMA op- eration to ensure that all rows remain refreshed provided the DMA transfer takes less than 2 ms (see Figure ...
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DP8409A Functional Mode Descriptions dress input latch is enabled onto the address bus About 14 ns after the column address is valid CAS goes low (t 14 ns) strobing the column address into the DRAMs e a When RAS and ...
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DP8409A Functional Mode Descriptions MODE 3b EXTERNALLY CONTROLLED ALL-RAS WRITE To select this mode B1 and B0 must first have been set Mode 7 This mode is useful at system initialization but under processor control The memory ...
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DP8409A Functional Mode Descriptions FIGURE 7a Read Cycle Timing (Mode 4) FIGURE 7b Write Cycle Timing (Mode 4) (Continued 8409– 8409– 16 ...
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DP8409A Functional Mode Descriptions Automatic CAS Generation In a normal memory access cycle CAS can be derived from inputs CASIN CASIN is high then R C going low switches the address output drivers from rows to ...
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DP8409A Functional Mode Descriptions FIGURE 8a Modes 5 6 Timing (CASIN High in Mode 6) FIGURE 8b Mode 6 Timing Extended CAS (Continued 8409 – 8409– 18 ...
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DP8409A Functional Mode Descriptions FIGURE 9 Hidden Refreshing (Mode 5) and Forced Refreshing (Mode 1) Timing (Continued 8409 – 19 ...
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DP8409A Functional Mode Descriptions TABLE II Memory Bank Decode Bank Select (Strobed by ADS) Enabled RAS RAS 0 1 RAS 1 0 RAS 1 1 RAS Note that RASIN going low earlier than t CSRL low ...
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... Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage V CC Storage Temperature Range b Input Voltage Output Current Lead Temperature (Soldering 10 seconds) Electrical Characteristics Symbol Parameter V Input Clamp Voltage ...
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Switching Characteristics DP8409A DP8409A (unless otherwise noted) (Notes The output load capacitance is typical for 4 banks DRAMs each or ...
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Switching Characteristics DP8409A DP8409A (unless otherwise noted) (Notes The output load capacitance is typical for 4 banks DRAMs each or ...
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Switching Characteristics DP8409A DP8409A (unless otherwise noted) (Notes The output load capacitance is typical for 4 banks DRAMs each or ...
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Switching Characteristics DP8409A (unless otherwise noted) (Notes The output load capacitance is typical for 4 banks DRAMs each or 88 ...
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Switching Characteristics DP8409A (unless otherwise noted) (Notes The output load capacitance is typical for 4 banks DRAMs each or 88 ...
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Applications If external control is preferred the DP8409A may be used in Mode Figure 6 If basic auto access and refresh are required then in cases where the user requires the minimum of external complexity ...
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Applications (Continued) FIGURE 13b DP8409A Auto Refresh 8409– 24 ...
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... Physical Dimensions inches (millimeters) Order Number DP8409AD DP8409AD-2 or DP8409AD-3 48-Lead Molded Dual-In-Line Package (N) Order Number DP8409AN DP8409AN-2 or DP8409AN-3 48-Lead Dual-In-Line Package (D) NS Package Number D48A NS Package Number N48A 23 ...
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... Hong Kong Ltd 49) 0-180-530 85 86 13th Floor Straight Block a Ocean Centre 5 Canton Rd 49) 0-180-530 85 85 Tsimshatsui Kowloon a Tel ( 49) 0-180-532 78 32 Hong Kong a 49) 0-180-532 93 58 Tel (852) 2737-1600 a Tel ( 49) 0-180-534 16 80 Fax (852) 2736-9960 a National Semiconductor Japan Ltd Tel 81-043-299-2309 Fax 81-043-299-2408 ...