FM21LD16 Ramtron Corporation, FM21LD16 Datasheet
FM21LD16
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FM21LD16 Summary of contents
Page 1
... These features make the FM21LD16 ideal for nonvolatile memory applications requiring frequent or rapid writes in the form of an SRAM. The FM21LD16 includes a low voltage monitor that blocks access to the memory array when V below V min. The memory is protected against an DD inadvertent access and data corruption under this condition ...
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... A(1:0) address inputs allow page mode operation when /CE is low. /WE Input Write Enable: A write cycle begins when /WE is asserted. The rising edge causes the FM21LD16 to write the data on the DQ bus to the F-RAM array. The falling edge of /WE latches a new column address for page mode write cycles. /OE Input Output Enable: When /OE is low, the FM21LD16 drives the data bus when valid read data is available ...
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... The /UB and /LB pins may be grounded if 1) the system does not perform byte writes and 2) the device is not configured as a 256Kx8. Rev. 1.0 Dec. 2009 A(1:0) Operation X Standby/Idle V Read Change Page Mode Read V Random Read V /CE-Controlled Write 2 V /WE-Controlled Write 3 V Page Mode Write X Starts Precharge FM21LD16 - 128Kx16 FRAM Page ...
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... In a /CE-controlled write, the /WE signal is asserted prior to beginning the memory cycle. That is, /WE is low when /CE falls. In this case, the device begins the memory cycle as a write. The FM21LD16 will not drive the data bus regardless of the state of /OE as long as /WE is low. Input data must be valid when /CE is deasserted high ...
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... A flow chart of the entire write protect operation is shown in Figure 2. The write-protect settings are nonvolatile. The factory default: all blocks are unprotected. FM21LD16 - 128Kx16 FRAM 1FFFFh – 1C000h 1BFFFh – 18000h 17FFFh – 14000h 13FFFh – 10000h 0FFFFh – ...
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... Read 0ECCCh Read 000FFh Read 1FF00h Write 1DAAAh 18h Write 0ECCCh E7h Write 0FF00h Read 00000h Rev. 1.0 Dec. 2009 Figure 2. Write-Protect State Machine - - - - - - ; bits 3 & complement of 18h - ; Data is don’t care - ; return to Normal Operation FM21LD16 - 128Kx16 FRAM Page ...
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... Software Write Protect Timing SRAM Drop-In Replacement The FM21LD16 has been designed drop-in replacement for standard asynchronous SRAMs. The device does not require /CE to toggle for each new address. /CE may remain low indefinitely. While /CE is low, the device automatically detects address changes and a new access is begun ...
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... Rev. 1.0 Dec. 2009 SS SS (JEDEC Std JESD22-A114-D) (JEDEC Std JESD22-C101-C) (JEDEC Std JESD22-A115-A) = 2.7V to 3.6V unless otherwise specified) DD Min 2.7 2.2 -0.3 2.4 = -1.0 mA) V -0.2 = -100 2.1 mA) = 100 A) FM21LD16 - 128Kx16 FRAM Ratings -1.0V to +4.5V -1.0V to +4.5V and V < +125 C 260 C TBD TBD TBD MSL-3 Typ Max Units Notes 3.3 3.6 ...
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... DD Min 110 (to /WE low) 15 (to /WE low 110 3.3V) DD Min - - FM21LD16 - 128Kx16 FRAM Max Units Notes - 110 Max ...
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... Rev. 1.0 Dec. 2009 = 2.7V to 3.6V unless otherwise specified) DD min. is reached) to First Access Time waveform. power ramp profiles. The behavior of the internal circuits is difficult to predict DD Min 10 Input and Output Timing Levels Output Load Capacitance FM21LD16 - 128Kx16 FRAM Min Max Units Notes 450 - ...
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... Although sequential column addressing is shown not required. Write Cycle Timing 1 (/WE-Controlled) Write Cycle Timing 2 (/CE-Controlled) CE A(16:0) WE DQ(15:0) UB/LB Rev. 1.0 Dec. 2009 Note: /OE (not shown) is low only to show effect of / pins BLC FM21LD16 - 128Kx16 FRAM Page ...
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... Write Cycle Timing 3 (/CE low) Note: /OE (not shown) is low only to show effect of / pins Page Mode Write Cycle Timing Although sequential column addressing is shown not required. Power Cycle Timing Rev. 1.0 Dec. 2009 FM21LD16 - 128Kx16 FRAM Page ...
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... FBGA Package Marking Scheme Legend: RAMTRON XXXXXX= part number, S=speed, P=package XXXXXXX-S-P LLLLLL= lot code, YY=year, WW=work week LLLLLLL YYWW Examples: FM21LD16, 60ns access time, “Green”/RoHS FBGA package, Lot C8556953BG1, Year 2009, Work Week 38 RAMTRON FM21LD16-60-BG C8556953BG1 0938 Rev. 1.0 Dec. 2009 Note: All dimensions in millimeters ...
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... Revision History Revision Date 1.0 12/22/2009 Rev. 1.0 Dec. 2009 Summary Initial release. FM21LD16 - 128Kx16 FRAM Page ...