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STK22C48

Document Number: 001-51000 Rev. **

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Hardware STORE Cycle

Parameter

Alt

Description

STK22C48

Unit

Min

Max

DHSB

[13, 16]

RECOVER,

HHQX

Hardware STORE High to Inhibit Off

700

PHSB

HLHX

Hardware STORE Pulse Width

HLBL

Hardware STORE Low to STORE Busy

300

Switching Waveform

Figure 12. Hardware STORE Cycle

Note

16. t

DHSB

is only applicable after t

STORE

is complete.

[+] Feedback

Содержание STK22C48

Страница 1: ...ctional Description The Cypress STK22C48 is a fast static RAM with a nonvolatile element in each memory cell The embedded nonvolatile elements incorporate QuantumTrap technology producing the world s most reliable nonvolatile memory The SRAM provides unlimited read and write cycles while independent nonvolatile data resides in the highly reliable QuantumTrap cell Data transfers from the SRAM to th...

Страница 2: ...ring read cycles Deasserting OE HIGH causes the IO pins to tri state VSS Ground Ground for the Device The device is connected to ground of the system VCC Power Supply Power Supply Inputs to the Device HSB Input or Output Hardware Store Busy HSB When LOW this output indicates a Hardware Store is in progress When pulled low external to the chip it initiates a nonvolatile STORE operation A weak inter...

Страница 3: ...ed Write or before the end of an CE controlled Write Keep OE HIGH during the entire Write cycle to avoid data bus contention on common IO lines If OE is left LOW internal circuitry turns off the output buffers tHZWE after WE goes LOW AutoStore Operation During normal operation the device draws current from VCC to charge a capacitor connected to the VCAP pin This stored charge is used by the chip t...

Страница 4: ...cts data from corruption during low voltage conditions by inhibiting all externally initiated STORE and Write operations The low voltage condition is detected when VCC is less than VSWITCH If the STK22C48 is in a Write mode both CE and WE are low at power up after a RECALL or after a STORE the Write is inhibited until a negative transition on CE or WE is detected This protects against inadvertent ...

Страница 5: ... so on must always program a unique NV pattern for example complex 4 byte pattern of 46 E6 49 53 hex or more random bytes as part of the final system manufacturing test to ensure these system routines work consistently Power up boot firmware routines should rewrite the nvSRAM into the desired state While the nvSRAM is shipped in a preset state best practice is to again rewrite the nvSRAM into the ...

Страница 6: ...cle rate Values obtained without output loads 10 mA ICC4 Average VCAP Current during AutoStore Cycle All Inputs Do Not Care VCC Max Average current for duration tSTORE 2 mA ISB1 4 Average Vcc Current Standby Cycling TTL Input Levels tRC 25 ns CE VIH tRC 45 ns CE VIH Commercial 25 18 mA mA Industrial 26 19 mA mA ISB2 4 VCC Standby Current CE VCC 0 2V All others VIN 0 2V or VCC 0 2V Standby current ...

Страница 7: ...nditions 28 SOIC 300 mil 28 SOIC 330 mil Unit ΘJA Thermal Resistance Junction to Ambient Test conditions follow standard test methods and procedures for measuring thermal impedance per EIA JESD51 TBD TBD C W ΘJC Thermal Resistance Junction to Case TBD TBD C W Figure 6 AC Test Loads AC Test Conditions 5 0V Output 30 pF R1 963Ω R2 512Ω 5 0V Output 5 pF R1 963Ω R2 512Ω For Tri state Specs Input Pulse...

Страница 8: ...5 5 ns tHZCE 8 tEHQZ Chip Disable to Output Inactive 10 15 ns tLZOE 8 tGLQX Output Enable to Output Active 0 0 ns tHZOE 8 tGHQZ Output Disable to Output Inactive 10 15 ns tPU 5 tELICCH Chip Enable to Power Active 0 0 ns tPD 5 tEHICCL Chip Disable to Power Standby 25 45 ns Switching Waveforms Figure 7 SRAM Read Cycle 1 Address Controlled 6 7 Figure 8 SRAM Read Cycle 2 CE and OE Controlled 6 W5 W W2...

Страница 9: ...s tHA tWHAX tEHAX Address Hold After End of Write 0 0 ns tHZWE 8 9 tWLQZ Write Enable to Output Disable 10 14 ns tLZWE 8 tWHQX Output Active After End of Write 5 5 ns Switching Waveforms Figure 9 SRAM Write Cycle 1 WE Controlled 10 11 Figure 10 SRAM Write Cycle 2 CE Controlled 10 11 tWC tSCE tHA tAW tSA tPWE tSD tHD tHZWE tLZWE ADDRESS CE WE DATA IN DATA OUT DATA VALID HIGH IMPEDANCE PREVIOUS DATA...

Страница 10: ...age Trigger Level 4 0 4 5 V VRESET Low Voltage Reset Level 3 6 V tVSBL 10 Low Voltage Trigger VSWITCH to HSB Low 300 ns Switching Waveform Figure 11 AutoStore Power Up RECALL WE Notes 12 tHRECALL starts from the time VCC rises above VSWITCH 13 CE and OE low for output behavior 14 CE and OE low and WE high for output behavior 15 HSB is asserted low for 1us when VCAP drops through VSWITCH If an SRAM...

Страница 11: ...n STK22C48 Unit Min Max tDHSB 13 16 tRECOVER tHHQX Hardware STORE High to Inhibit Off 700 ns tPHSB tHLHX Hardware STORE Pulse Width 15 ns tHLBL Hardware STORE Low to STORE Busy 300 ns Switching Waveform Figure 12 Hardware STORE Cycle Note 16 tDHSB is only applicable after tSTORE is complete Feedback ...

Страница 12: ...IC 300 mil Commercial STK22C48 NF45 51 85026 28 pin SOIC 300 mil STK22C48 SF45TR 51 85058 28 pin SOIC 330 mil STK22C48 SF45 51 85058 28 pin SOIC 330 mil STK22C48 NF45ITR 51 85026 28 pin SOIC 300 mil Industrial STK22C48 NF45I 51 85026 28 pin SOIC 300 mil STK22C48 SF45ITR 51 85058 28 pin SOIC 330 mil STK22C48 SF45I 51 85058 28 pin SOIC 330 mil All parts are Pb free The above table contains Final inf...

Страница 13: ... 0125 3 17 0 015 0 38 0 050 1 27 0 013 0 33 0 019 0 48 0 026 0 66 0 032 0 81 0 697 17 70 0 713 18 11 0 004 0 10 1 14 15 28 PART S28 3 STANDARD PKG SZ28 3 LEAD FREE PKG MIN MAX NOTE 1 JEDEC STD REF MO 119 2 BODY LENGTH DIMENSION DOES NOT INCLUDE MOLD PROTRUSION END FLASH BUT MOLD PROTRUSION END FLASH SHALL NOT EXCEED 0 010 in 0 254 mm PER SIDE 3 DIMENSIONS IN INCHES 4 PACKAGE WEIGHT 0 85gms DOES IN...

Страница 14: ... as specified in the applicable agreement Any reproduction modification translation compilation or representation of this Source Code except as specified above is prohibited without the express written permission of Cypress Disclaimer CYPRESS MAKES NO WARRANTY OF ANY KIND EXPRESS OR IMPLIED WITH REGARD TO THIS MATERIAL INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITN...

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