STK12C68 64 Kbit (8 K x 8) AutoStore nvSRAM Functional Description ■ 25 ns, 35 ns, and 45 ns access times ■ Hands off automatic STORE on power-down with external 68 µF capacitor ■ STORE to QuantumTrap nonvolatile elements is initiated by software, hardware, or AutoStore on power-down ■ RECALL to SRAM initiated by software or power-up ■ Unlimited read, write, and recall cycles ■ 1,000,000 STORE cycles to QuantumTrap ■ 100 year data retention to QuantumTrap ■ Single 5 V + 10% operation ■ Commercial and industrial temperatures ■ 28-pin (330 mil) SOIC, 28-pin (300 mil) PDIP, 28-pin (600 mil) PDIP packages ■ 28-pin (300 mil) CDIP and 28-pad (350 mil) LCC packages ■ RoHS compliance The Cypress STK12C68 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 the nonvolatile elements (the STORE operation) takes place automatically at power-down. On power-up, data is restored to the SRAM (the RECALL operation) from the nonvolatile memory. Both the STORE and RECALL operations are also available under software control. A hardware STORE is initiated with the HSB pin. For a complete list of related documentation, click here. Logic Block Diagram A5 A7 A8 A9 A 11 STATIC RAM ARRAY 128 X 512 RECALL STORE/ RECALL CONTROL DQ 0 DQ 4 DQ 5 DQ 6 A0 - A 12 COLUMN I/O INPUT BUFFERS DQ 2 DQ 3 HSB SOFTWARE DETECT A 12 DQ 1 VCAP POWER CONTROL STORE ROW DECODER A6 VCC Quantum Trap 128 X 512 COLUMN DEC A 0 A 1 A 2 A 3 A 4 A 10 DQ 7 OE CE WE Cypress Semiconductor Corporation Document Number: 001-51027 Rev. *H • 198 Champion Court • San Jose, CA 95134-1709 • 408-943-2600 Revised November 17, 2014 Not Recommended for New Designs Features STK12C68 Pin Configurations ........................................................... Pin Definitions .................................................................. Device Operation .............................................................. SRAM Read ....................................................................... SRAM Write ....................................................................... AutoStore Operation ........................................................ AutoStore Inhibit Mode .................................................... Hardware STORE (HSB) Operation................................. Hardware RECALL (Power-up)........................................ Software STORE ............................................................... Software RECALL............................................................. Data Protection ................................................................. Noise Considerations....................................................... Hardware Protect.............................................................. Low Average Active Power.............................................. Preventing Store............................................................... Best Practices................................................................... Maximum Ratings............................................................. Operating Range............................................................... DC Electrical Characteristics .......................................... Document Number: 001-51027 Rev. *H 3 3 4 4 4 4 5 5 5 5 6 6 6 6 6 6 7 8 8 8 Data Retention and Endurance ....................................... 9 Capacitance ...................................................................... 9 Thermal Resistance.......................................................... 9 AC Test Conditions .......................................................... 9 AC Switching Characteristics ....................................... 10 SRAM Read Cycle .................................................... 10 SRAM Write Cycle..................................................... 11 AutoStore or Power-up RECALL................................... 12 Software Controlled STORE/RECALL Cycle................ 13 Hardware STORE Cycle ................................................. 14 Switching Waveform ...................................................... 14 Part Numbering Nomenclature...................................... 15 Ordering Information...................................................... 15 Package Diagrams.......................................................... 16 Document History Page ................................................. 21 Sales, Solutions, and Legal Information ...................... 22 Worldwide Sales and Design Support....................... 22 Products .................................................................... 22 PSoC Solutions ......................................................... 22 Page 2 of 22 Not Recommended for New Designs Contents STK12C68 Pin Configurations Pin Definitions Pin Name Alt A0–A12 I/O Type Input DQ0-DQ7 Description Address Inputs. Used to select one of the 8,192 bytes of the nvSRAM. Input or Output Bidirectional Data I/O Lines. Used as input or output lines depending on operation. WE W Input Write Enable Input, Active LOW. When the chip is enabled and WE is LOW, data on the I/O pins is written to the specific address location. CE E Input Chip Enable Input, Active LOW. When LOW, selects the chip. When HIGH, deselects the chip. G Input Output Enable, Active LOW. The active LOW OE input enables the data output buffers during read cycles. Deasserting OE HIGH causes the I/O pins to tristate. OE 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 internal pull up resistor keeps this pin high if not connected (connection optional). VCAP Power Supply AutoStore Capacitor. Supplies power to nvSRAM during power loss to store data from SRAM to nonvolatile elements. Document Number: 001-51027 Rev. *H Page 3 of 22 Not Recommended for New Designs Figure 1. 28-Pin SOIC/DIP and LLC STK12C68 The STK12C68 nvSRAM is made up of two functional components paired in the same physical cell. These are an SRAM memory cell and a nonvolatile QuantumTrap cell. The SRAM memory cell operates as a standard fast static RAM. Data in the SRAM is transferred to the nonvolatile cell (the STORE operation) or from the nonvolatile cell to SRAM (the RECALL operation). This unique architecture enables the storage and recall of all cells in parallel. During the STORE and RECALL operations, SRAM Read and Write operations are inhibited. The STK12C68 supports unlimited reads and writes similar to a typical SRAM. In addition, it provides unlimited RECALL operations from the nonvolatile cells and up to one million STORE operations. 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 to perform a single STORE operation. If the voltage on the VCC pin drops below VSWITCH, the part automatically disconnects the VCAP pin from VCC. A STORE operation is initiated with power provided by the VCAP capacitor. Figure 2 shows the proper connection of the storage capacitor (VCAP) for automatic store operation. A charge storage capacitor between 68 µF and 220 µF (+20%) rated at 6 V should be provided. The voltage on the VCAP pin is driven to 5 V by a charge pump internal to the chip. A pull-up is placed on WE to hold it inactive during power-up. Figure 2. AutoStore Mode A Write cycle is performed whenever CE and WE are LOW and HSB is HIGH. The address inputs must be stable prior to entering the Write cycle and must remain stable until either CE or WE goes HIGH at the end of the cycle. The data on the common I/O pins DQ0–7 are written into the memory if it has valid tSD, before the end of a WE controlled 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 I/O lines. If OE is left LOW, internal circuitry turns off the output buffers tHZWE after WE goes LOW. AutoStore Operation The STK12C68 stores data to nvSRAM using one of three storage operations: 1. Hardware store activated by HSB 2. Software store activated by an address sequence 3. AutoStore on device power-down AutoStore operation is a unique feature of QuantumTrap technology and is enabled by default on the STK12C68. Document Number: 001-51027 Rev. *H WE 10k Ohm Vcc HSB 0.15 F Bypass SRAM Write VCAP 68 5F 6v, +20% The STK12C68 performs a Read cycle whenever CE and OE are LOW while WE and HSB are HIGH. The address specified on pins A0–12 determines the 8,192 data bytes accessed. When the Read is initiated by an address transition, the outputs are valid after a delay of tAA (Read cycle 1). If the Read is initiated by CE or OE, the outputs are valid at tACE or at tDOE, whichever is later (Read cycle 2). The data outputs repeatedly respond to address changes within the tAA access time without the need for transitions on any control input pins, and remains valid until another address change or until CE or OE is brought HIGH, or WE or HSB is brought LOW. 10k Ohm SRAM Read Vss In system power mode, both VCC and VCAP are connected to the +5 V power supply without the 68 F capacitor. In this mode, the AutoStore function of the STK12C68 operates on the stored system charge as power goes down. The user must, however, guarantee that VCC does not drop below 3.6 V during the 10 ms STORE cycle. To reduce unnecessary nonvolatile stores, AutoStore, and Hardware Store operations are ignored, unless at least one Write operation has taken place since the most recent STORE or RECALL cycle. Software initiated STORE cycles are performed regardless of whether a Write operation has taken place. An optional pull-up resistor is shown connected to HSB. The HSB signal is monitored by the system to detect if an AutoStore cycle is in progress. Page 4 of 22 Not Recommended for New Designs Device Operation STK12C68 WE HSB the STK12C68 continues SRAM operations for tDELAY. During tDELAY, multiple SRAM Read operations take place. If a Write is in progress when HSB is pulled LOW, it allows a time, tDELAY to complete. However, any SRAM Write cycles requested after HSB goes LOW are inhibited until HSB returns HIGH. During any STORE operation, regardless of how it is initiated, the STK12C68 continues to drive the HSB pin LOW, releasing it only when the STORE is complete. After completing the STORE operation, the STK12C68 remains disabled until the HSB pin returns HIGH. If HSB is not used, it is left unconnected. Hardware RECALL (Power-up) During power-up or after any low power condition (VCC < VRESET), an internal RECALL request is latched. When VCC once again exceeds the sense voltage of VSWITCH, a RECALL cycle is automatically initiated and takes tHRECALL to complete. Vss If the STK12C68 is in a Write state at the end of power-up RECALL, the SRAM data is corrupted. To help avoid this situation, a 10 k resistor is connected either between WE and system VCC or between CE and system VCC. Software STORE If the power supply drops faster than 20 us/volt before Vcc reaches VSWITCH, then a 2.2 resistor should be connected between VCC and the system supply to avoid momentary excess of current between VCC and VCAP. AutoStore Inhibit Mode If an automatic STORE on power loss is not required, then VCC is tied to ground and +5 V is applied to VCAP (Figure 3). This is the AutoStore Inhibit mode, where the AutoStore function is disabled. If the STK12C68 is operated in this configuration, references to VCC are changed to VCAP throughout this data sheet. In this mode, STORE operations are triggered through software control or the HSB pin. To enable or disable Autostore using an I/O port pin see Preventing Store on page 6. It is not permissible to change between these three options “on the fly”. Hardware STORE (HSB) Operation The STK12C68 provides the HSB pin for controlling and acknowledging the STORE operations. The HSB pin is used to request a hardware STORE cycle. When the HSB pin is driven LOW, the STK12C68 conditionally initiates a STORE operation after tDELAY. An actual STORE cycle only begins if a Write to the SRAM takes place since the last STORE or RECALL cycle. The HSB pin also acts as an open drain driver that is internally driven LOW to indicate a busy condition, while the STORE (initiated by any means) is in progress. SRAM Read and Write operations, that are in progress when HSB is driven LOW by any means, are given time to complete before the STORE operation is initiated. After HSB goes LOW, Document Number: 001-51027 Rev. *H Data is transferred from the SRAM to the nonvolatile memory by a software address sequence. The STK12C68 software STORE cycle is initiated by executing sequential CE controlled Read cycles from six specific address locations in exact order. During the STORE cycle, an erase of the previous nonvolatile data is first performed followed by a program of the nonvolatile elements. When a STORE cycle is initiated, input and output are disabled until the cycle is completed. Because a sequence of Reads from specific addresses is used for STORE initiation, it is important that no other Read or Write accesses intervene in the sequence. If they intervene, the sequence is aborted and no STORE or RECALL takes place. To initiate the software STORE cycle, the following Read sequence is performed: 1. Read address 0x0000, Valid READ 2. Read address 0x1555, Valid READ 3. Read address 0x0AAA, Valid READ 4. Read address 0x1FFF, Valid READ 5. Read address 0x10F0, Valid READ 6. Read address 0x0F0F, Initiate STORE cycle The software sequence is clocked with CE controlled Reads or OE controlled Reads. When the sixth address in the sequence is entered, the STORE cycle commences and the chip is disabled. It is important that Read cycles and not Write cycles are used in the sequence. It is not necessary that OE is LOW for a valid sequence. After the tSTORE cycle time is fulfilled, the SRAM is again activated for Read and Write operation. Page 5 of 22 Not Recommended for New Designs Vcc 10k O hm VCAP 10k Ohm 0.15 F Bypass Figure 3. AutoStore Inhibit Mode STK12C68 Data is transferred from the nonvolatile memory to the SRAM by a software address sequence. A software RECALL cycle is initiated with a sequence of Read operations in a manner similar to the software STORE initiation. To initiate the RECALL cycle, the following sequence of CE controlled Read operations is performed: 1. Read address 0x0000, Valid READ 2. Read address 0x1555, Valid READ 3. Read address 0x0AAA, Valid READ 4. Read address 0x1FFF, Valid READ 5. Read address 0x10F0, Valid READ 6. Read address 0x0F0E, Initiate RECALL cycle ■ The duty cycle of chip enable ■ The overall cycle rate for accesses ■ The ratio of Reads to Writes ■ CMOS versus TTL input levels ■ The operating temperature ■ The VCC level I/O loading Figure 4. Current Versus Cycle Time (Read) ■ Not Recommended for New Designs Software RECALL Internally, RECALL is a two step procedure. First, the SRAM data is cleared; then, the nonvolatile information is transferred into the SRAM cells. After the tRECALL cycle time, the SRAM is again ready for Read and Write operations. The RECALL operation does not alter the data in the nonvolatile elements. The nonvolatile data can be recalled an unlimited number of times. Data Protection The STK12C68 protects 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 STK12C68 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 writes during power-up or brown out conditions. Figure 5. Current Versus Cycle Time (Write) Noise Considerations The STK12C68 is a high speed memory. It must have a high frequency bypass capacitor of approximately 0.1 µF connected between VCC and VSS, using leads and traces that are as short as possible. As with all high speed CMOS ICs, careful routing of power, ground, and signals reduce circuit noise. Hardware Protect The STK12C68 offers hardware protection against inadvertent STORE operation and SRAM Writes during low voltage conditions. When VCAP<VSWITCH, all externally initiated STORE operations and SRAM Writes are inhibited. AutoStore can be completely disabled by tying VCC to ground and applying +5 V to VCAP. This is the AutoStore Inhibit mode; in this mode, STOREs are only initiated by explicit request using either the software sequence or the HSB pin. Low Average Active Power CMOS technology provides the STK12C68 the benefit of drawing significantly less current when it is cycled at times longer than 50 ns. Figure 4 shows the relationship between ICC and Read or Write cycle time. Worst case current consumption is shown for both CMOS and TTL input levels (commercial temperature range, VCC = 5.5 V, 100% duty cycle on chip enable). Only standby current is drawn when the chip is disabled. The overall average current drawn by the STK12C68 depends on the following items: Document Number: 001-51027 Rev. *H Preventing Store The STORE function is disabled by holding HSB high with a driver capable of sourcing 30 mA at a VOH of at least 2.2 V, because it must overpower the internal pull-down device. This device drives HSB LOW for 20 s at the onset of a STORE. When the STK12C68 is connected for AutoStore operation (system VCC connected to VCC and a 68 F capacitor on VCAP) and VCC crosses VSWITCH on the way down, the STK12C68 attempts to pull HSB LOW. If HSB does not actually get below VIL, the part stops trying to pull HSB LOW and abort the STORE attempt. Page 6 of 22 STK12C68 Best Practices nvSRAM products have been used effectively for over 15 years. While ease-of-use is one of the product’s main system values, experience gained working with hundreds of applications has resulted in the following suggestions as best practices: ■ The nonvolatile cells in an nvSRAM are programmed on the test floor during final test and quality assurance. Incoming inspection routines at customer or contract manufacturer’s sites sometimes reprograms these values. Final NV patterns are typically repeating patterns of AA, 55, 00, FF, A5, or 5A. The end product’s firmware should not assume that an NV array is in a set programmed state. Routines that check memory content values to determine first time system configuration, cold or warm boot status, and 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 ■ 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 desired state as a safeguard against events that might flip the bit inadvertently (program bugs, incoming inspection routines, and so on). ■ The VCAP value specified in this data sheet includes a minimum and a maximum value size. The best practice is to meet this requirement and not exceed the maximum VCAP value because the higher inrush currents may reduce the reliability of the internal pass transistor. Customers who want to use a larger VCAP value to make sure there is extra store charge should discuss their VCAP size selection with Cypress. Table 1. Hardware Mode Selection CE WE HSB A12–A0 Mode I/O Power H X H X Not Selected Output High Z Standby L H H X Read SRAM Output Data Active[3] L L H X Write SRAM Input Data Active X X L X Nonvolatile STORE Output High Z ICC2[1] L H H 0x0000 0x1555 0x0AAA 0x1FFF 0x10F0 0x0F0F Read SRAM Read SRAM Read SRAM Read SRAM Read SRAM Nonvolatile STORE Output Data Output Data Output Data Output Data Output Data Output High Z Active ICC2[2, 3] L H H 0x0000 0x1555 0x0AAA 0x1FFF 0x10F0 0x0F0E Read SRAM Read SRAM Read SRAM Read SRAM Read SRAM Nonvolatile RECALL Output Data Output Data Output Data Output Data Output Data Output High Z Active[2, 3] Notes 1. HSB STORE operation occurs only if an SRAM Write is done since the last nonvolatile cycle. After the STORE (If any) completes, the part goes into standby mode, inhibiting all operations until HSB rises. 2. The six consecutive addresses must be in the order listed. WE must be high during all six consecutive CE controlled cycles to enable a nonvolatile cycle. 3. I/O state assumes OE < VIL. Activation of nonvolatile cycles does not depend on state of OE. Document Number: 001-51027 Rev. *H Page 7 of 22 Not Recommended for New Designs manufacturing test to ensure these system routines work consistently. STK12C68 Maximum Ratings Voltage on DQ0-7 or HSB .................... –0.5 V to VCC + 0.5 V Exceeding maximum ratings may shorten the useful life of the device. These user guidelines are not tested. Storage Temperature ............................... –65 C to +150 C Power Dissipation......................................................... 1.0 W DC output Current (1 output at a time, 1s duration) .... 15 mA Range Voltage on Input Relative to GND...................–0.5 V to 7.0 V Commercial Voltage on Input Relative to VSS ......... –0.6 V to VCC + 0.5 V Industrial Ambient Temperature VCC 0 C to +70C 4.5 V to 5.5 V –40 C to +85 C 4.5 V to 5.5 V DC Electrical Characteristics Over the operating range (VCC = 4.5V to 5.5V) [4] Parameter Description Test Conditions Min Max Unit ICC1 Average VCC current tRC = 25 ns tRC = 35 ns tRC = 45 ns Dependent on output loading and cycle rate. Values obtained without output loads. IOUT = 0 mA. – 85 75 65 mA mA mA ICC2 Average VCC current during STORE All Inputs Do Not Care, VCC = Max Average current for duration tSTORE – 3 mA ICC3 Average VCC current at WE > (VCC – 0.2 V). All other inputs cycling. tRC= 200 ns, 5 V, 25 °C Dependent on output loading and cycle rate. Values obtained without output loads. Typical – 10 mA ICC4 Average VCAP Current All Inputs Do Not Care, VCC = Max during AutoStore Cycle Average current for duration tSTORE – 2 mA ISB1[5] VCC standby current (standby, cycling TTL input levels) tRC = 25 ns, CE > VIH tRC = 35 ns, CE > VIH tRC = 45 ns, CE > VIH – 27 24 20 mA mA mA ISB2 [5] VCC standby current CE > (VCC – 0.2 V). All others VIN < 0.2 V or > Commercial (VCC – 0.2 V). Standby current level after nonvolatile cycle is complete. Industrial Inputs are static. f = 0 MHz. – 1.5 mA – 2.5 mA IIX Input leakage current VCC = Max, VSS < VIN < VCC –1 +1 A IIX Input leakage current VCC = Max, VSS < VIN < VCC –1 +1 A IOZ Off State Output Leakage Current VCC = Max, VSS < VIN < VCC, CE or OE > VIH or WE < VIL –-5 +5 A VIH Input HIGH voltage 2.2 VCC + 0.5 V VIL Input LOW voltage VSS – 0.5 0.8 V VOH Output HIGH voltage IOUT = –4 mA 2.4 VOL Output LOW voltage IOUT = 8 mA – 0.4 V VBL Logic ‘0’ voltage on HSB output IOUT = 3 mA – 0.4 V VCAP Storage capacitor Between VCAP pin and VSS, 6 V rated. 68 µF +20% nominal 54 260 µF V Notes 4. VCC reference levels throughout this data sheet refer to VCC if that is where the power supply connection is made, or VCAP if VCC is connected to ground. 5. CE > VIH does not produce standby current levels until any nonvolatile cycle in progress has timed out. Document Number: 001-51027 Rev. *H Page 8 of 22 Not Recommended for New Designs Operating Range Temperature under Bias ........................... –55 C to +125 C STK12C68 Data Retention and Endurance Parameter Description DATAR Data retention NVC Nonvolatile STORE operations Min Unit 100 Years 1,000 K Capacitance Parameter Description CIN Input capacitance COUT Output capacitance Test Conditions TA = 25 C, f = 1 MHz, VCC = 0 to 3.0 V Max Unit 8 pF 7 pF Thermal Resistance In the following table, the thermal resistance parameters are listed.[6] Parameter Description JA Thermal resistance (junction to ambient) JC Thermal resistance (junction to case) Test Conditions Test conditions follow standard test methods and procedures for measuring thermal impedance, per EIA / JESD51. 28-PDIP 28-SOIC (300 mil) 28-PDIP (600 mil) 28-CDIP 28-LCC Unit 46.55 45.16 55.84 46.1 95.31 C/W 27.95 31.62 25.74 5.01 9.01 C/W Figure 6. AC Test Loads R1 963 For Tristate Specs R1 963 5.0 V 5.0 V Output Output 30 pF R2 512 5 pF R2 512 AC Test Conditions Input pulse levels.................................................... 0 V to 3 V Input rise and fall times (10% to 90%).......................... <5 ns Input and output timing reference levels ...........................1.5 Note 6. These parameters are guaranteed by design and are not tested. Document Number: 001-51027 Rev. *H Page 9 of 22 Not Recommended for New Designs In the following table, the capacitance parameters are listed.[6] STK12C68 AC Switching Characteristics SRAM Read Cycle 25 ns Description Chip enable access time Read cycle time Address access time Output enable to data valid Output hold after address change Chip enable to output active Chip disable to output inactive Output enable to output active Output disable to output inactive Chip enable to power active Chip disable to power standby 35 ns 45 ns Min Max Min Max Min Max – 25 – – 5 5 – 0 – 0 – 25 – 25 10 – – 10 – 10 – 25 – 35 – – 5 5 – 0 – 0 – 35 – 35 15 – – 10 – 10 – 35 – 45 – – 5 5 – 0 – 0 – 45 – 45 20 – – 12 – 12 – 45 Unit ns ns ns ns ns ns ns ns ns ns ns Switching Waveforms Figure 7. SRAM Read Cycle 1: Address Controlled [7, 8] tRC ADDRESS t AA tOHA DQ (DATA OUT) DATA VALID Figure 8. SRAM Read Cycle 2: CE and OE Controlled [7] tRC ADDRESS tLZCE CE tACE tPD tHZCE OE tLZOE DQ (DATA OUT) t PU ICC tHZOE tDOE DATA VALID ACTIVE STANDBY Notes 7. WE and HSB must be High during SRAM Read cycles. 8. Device is continuously selected with CE and OE both Low. 9. Measured ±200 mV from steady state output voltage. Document Number: 001-51027 Rev. *H Page 10 of 22 Not Recommended for New Designs Parameter Cypress Alt Parameter tELQV tACE tAVAV, tELEH tRC [7] tAVQV tAA [8] tGLQV tDOE tAXQX tOHA [8] tELQX tLZCE [9] tEHQZ tHZCE [9] [9] tGLQX tLZOE tGHQZ tHZOE [9] tELICCH tPU [6] [6] tEHICCL tPD STK12C68 SRAM Write Cycle Cypress Parameter 25 ns Description Alt tAVAV tWLWH, tWLEH tELWH, tELEH tDVWH, tDVEH tWHDX, tEHDX tAVWH, tAVEH tAVWL, tAVEL tWHAX, tEHAX tWLQZ tWHQX tWC tPWE tSCE tSD tHD tAW tSA tHA tHZWE [9,10] tLZWE [9] Write cycle time Write pulse width Chip enable to end of write Data setup to end of write Data hold after end of write Address setup to end of write Address setup to start of write Address hold after end of write Write enable to output disable Output active after end of write 35 ns 45 ns Min Max Min Max Min Max 25 20 20 10 0 20 0 0 – 5 – – – – – – – – 10 – 35 25 25 12 0 25 0 0 – 5 – – – – – – – – 13 – 45 30 30 15 0 30 0 0 – 5 – – – – – – – – 14 – Unit ns ns ns ns ns ns ns ns ns ns Switching Waveforms Figure 9. SRAM Write Cycle 1: WE Controlled [11, 12] tWC ADDRESS tHA tSCE CE tAW tSA tPWE WE tSD tHD DATA VALID DATA IN tHZWE DATA OUT tLZWE HIGH IMPEDANCE PREVIOUS DATA Figure 10. SRAM Write Cycle 2: CE Controlled [11, 12] tWC ADDRESS CE WE tHA tSCE tSA tAW tPWE tSD DATA IN DATA OUT tHD DATA VALID HIGH IMPEDANCE Notes 10. If WE is Low when CE goes Low, the outputs remain in the high impedance state. 11. HSB must be high during SRAM Write cycles. 12. CE or WE must be greater than VIH during address transitions. Document Number: 001-51027 Rev. *H Page 11 of 22 Not Recommended for New Designs Parameter STK12C68 AutoStore or Power-up RECALL Alt tHRECALL [13] tSTORE [14, 15, 16] tDELAY [9, 15] VSWITCH VRESET tVCCRISE tVSBL[11] tRESTORE tHLHZ tHLQZ , tBLQZ Description Power-up RECALL duration STORE cycle duration Time allowed to complete SRAM cycle Low voltage trigger level Low voltage reset level VCC rise time Low voltage trigger (VSWITCH) to HSB Low STK12C68 Min Max – 550 – 10 1 – 4.0 4.5 – 3.9 150 – – 300 Unit s ms s V V s ns Switching Waveform Figure 11. AutoStore/Power-up RECALL WE Notes 13. tHRECALL starts from the time VCC rises above VSWITCH. 14. CE and OE low for output behavior. 15. CE and OE low and WE high for output behavior. 16. HSB is asserted low for 1us when VCAP drops through VSWITCH. If an SRAM Write has not taken place since the last nonvolatile cycle, HSB is released and no store takes place. Document Number: 001-51027 Rev. *H Page 12 of 22 Not Recommended for New Designs Parameter STK12C68 Software Controlled STORE/RECALL Cycle The software controlled STORE/RECALL cycle follows. [18] Alt Description 25 ns 35 ns 45 ns Min Max Min Max Min Max Unit tRC[14] tAVAV STORE/RECALL initiation cycle time 25 – 35 – 45 – ns tSA[17] tCW[17] tHACE[17] tAVEL Address setup time 0 – 0 – 0 – ns tELEH Clock pulse width 20 – 25 – 30 – ns tELAX Address hold time 20 – 20 – 20 – ns RECALL duration – 20 – 20 – 20 s tRECALL Switching Waveform Figure 12. CE Controlled Software STORE/RECALL Cycle [18] tRC ADDRESS # 1 ADDRESS tSA tRC ADDRESS # 6 tSCE CE tHACE OE t STORE / t RECALL DQ (DATA) DATA VALID DATA VALID HIGH IMPEDANCE Notes 17. The software sequence is clocked on the falling edge of CE without involving OE (double clocking aborts the sequence). 18. The six consecutive addresses must be read in the order listed in Table 1 on page 7. WE must be HIGH during all six consecutive cycles. Document Number: 001-51027 Rev. *H Page 13 of 22 Not Recommended for New Designs Parameter STK12C68 Hardware STORE Cycle tSTORE [9, 14] tDHSB tPHSB [14, 19] Alt tHLHZ Description STK12C68 Min STORE Cycle duration 10 tRECOVER, tHHQX Hardware STORE High to inhibit off tHLHX tHLBL Hardware STORE pulse width Hardware STORE Low to STORE busy Max 700 15 Unit ms ns ns 300 ns Switching Waveform Figure 13. Hardware STORE Cycle Note 19. tDHSB is only applicable after tSTORE is complete. Document Number: 001-51027 Rev. *H Page 14 of 22 Not Recommended for New Designs Parameter STK12C68 Part Numbering Nomenclature STK12C68 - S F 45 I TR Temperature Range: C - Commercial (0 to 70 °C) I - Industrial (–40 to 85 °C) Lead Finish Speed: 25 - 25 ns 35 - 35 ns 45 - 45 ns F = 100% Sn (Matte Tin) Package: S = Plastic 28-pin 330 mil SOIC P = Plastic 28-pin 300 mil DIP W = Plastic 28-pin 600 mil DIP C = Ceramic 28-pin 300 mil DIP L = Ceramic 28-pin LLC Ordering Information These parts are not recommended for new designs. They are in production to support ongoing production programs only. Speed (ns) 25 45 Ordering Code Package Diagram Package Type STK12C68-SF25TR 51-85058 28-pin SOIC (330 mil) STK12C68-SF25 51-85058 28-pin SOIC (330 mil) STK12C68-SF25ITR 51-85058 28-pin SOIC (330 mil) STK12C68-SF25I 51-85058 28-pin SOIC (330 mil) STK12C68-SF45TR 51-85058 28-pin SOIC (330 mil) STK12C68-SF45 51-85058 28-pin SOIC (330 mil) STK12C68-SF45ITR 51-85058 28-pin SOIC (330 mil) STK12C68-SF45I 51-85058 28-pin SOIC (330 mil) Operating Range Commercial Industrial Commercial Industrial All parts are Pb-free. The above table contains Final information. Contact your local Cypress sales representative for availability of these parts Document Number: 001-51027 Rev. *H Page 15 of 22 Not Recommended for New Designs Packaging Option: TR = Tape and Reel Blank = Tube STK12C68 Package Diagrams 51-85058 *C Document Number: 001-51027 Rev. *H Page 16 of 22 Not Recommended for New Designs Figure 14. 28-Pin (330 Mil) SOIC (51-85058) STK12C68 Package Diagrams (continued) Not Recommended for New Designs Figure 15. 28-Pin (300 Mil) PDIP (51-85014) 51-85014 *G Document Number: 001-51027 Rev. *H Page 17 of 22 STK12C68 Package Diagrams (continued) 51-85017 *E Document Number: 001-51027 Rev. *H Page 18 of 22 Not Recommended for New Designs Figure 16. 28-Pin (600 Mil) PDIP (51-85017) STK12C68 Package Diagrams (continued) 001-51695 *B Document Number: 001-51027 Rev. *H Page 19 of 22 Not Recommended for New Designs Figure 17. 28-Pin (300 Mil) Side Braze DIL (001-51695) STK12C68 Package Diagrams (continued) 001-51696 *B Document Number: 001-51027 Rev. *H Page 20 of 22 Not Recommended for New Designs Figure 18. 28-Pad (350 Mil) LCC (001-51696) STK12C68 Document History Page Document Title: STK12C68 64 Kbit (8 K x 8) AutoStore nvSRAM Document Number: 001-51027 ECN No. Orig. of Change Submission Date Description of Change ** 2606744 GVCH 01/30/2009 New data sheet *A 2826441 GVCH 12/11/2009 Added following text in the Ordering Information section: “These parts are not recommended for new designs. In production to support ongoing production programs only.” Added watermark in PDF stating “Not recommended for new designs. In production to support ongoing production programs only.” Added Contents on page 2. *B 3054694 GVCH 10/12/2010 Removed the following prune parts from the document; STK12C68-C35I STK12C68-C45 STK12C68-L35 STK12C68-L35I STK12C68-L45 STK12C68-L45I STK12C68-PF25 STK12C68-PF45 STK12C68-PF45I STK12C68-WF45 STK12C68-WF45I STK12C68-WF25 *C 3189527 GVCH 03/07/2011 Added watermark in PDF stating “Not recommended for new designs. In production to support ongoing production programs only.” *D 3208949 GVCH 03/30/11 Removed pruned part “STK12C68-C35” from the ordering code information. *E 3229103 GVCH 04/15/11 Added missing watermark “Not Recommended for New Designs. In production to support ongoing production programs only.” that was found in *C revision. *F 3402039 GVCH 10/12/2011 Removed pruned device STK12C68-WF25I from Ordering Information. Updated Package Diagrams and Table of Contents. *G 4303589 GVCH 03/21/2014 Figure 17: Updated Package diagram from *A to *B revision Figure 18: Updated Package diagram from *A to *B revision Sunset review *H 4571551 GVCH 11/17/2014 Updated documentation related hyperlink in page 1 Removed pruned parts - STK12C68-PF25I, STK12C68-C45I Document Number: 001-51027 Rev. *H Page 21 of 22 Not Recommended for New Designs Rev. STK12C68 Sales, Solutions, and Legal Information Worldwide Sales and Design Support Cypress maintains a worldwide network of offices, solution centers, manufacturer’s representatives, and distributors. To find the office closest to you, visit us at cypress.com/sales. Automotive Clocks & Buffers Interface Lighting & Power Control PSoC Solutions cypress.com/go/automotive psoc.cypress.com/solutions cypress.com/go/clocks PSoC 1 | PSoC 3 | PSoC 5 cypress.com/go/interface cypress.com/go/powerpsoc cypress.com/go/plc Memory Optical & Image Sensing PSoC Touch Sensing USB Controllers Wireless/RF cypress.com/go/memory cypress.com/go/image cypress.com/go/psoc cypress.com/go/touch cypress.com/go/USB cypress.com/go/wireless © Cypress Semiconductor Corporation, 2009-2014. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in a Cypress product. Nor does it convey or imply any license under patent or other rights. Cypress products are not warranted nor intended to be used for medical, life support, life saving, critical control or safety applications, unless pursuant to an express written agreement with Cypress. Furthermore, Cypress does not authorize its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress against all charges. Any Source Code (software and/or firmware) is owned by Cypress Semiconductor Corporation (Cypress) and is protected by and subject to worldwide patent protection (United States and foreign), United States copyright laws and international treaty provisions. Cypress hereby grants to licensee a personal, non-exclusive, non-transferable license to copy, use, modify, create derivative works of, and compile the Cypress Source Code and derivative works for the sole purpose of creating custom software and or firmware in support of licensee product to be used only in conjunction with a Cypress integrated circuit 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 FITNESS FOR A PARTICULAR PURPOSE. Cypress reserves the right to make changes without further notice to the materials described herein. Cypress does not assume any liability arising out of the application or use of any product or circuit described herein. Cypress does not authorize its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress’ product in a life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress against all charges. Use may be limited by and subject to the applicable Cypress software license agreement. Document Number: 001-51027 Rev. *H Revised November 17, 2014 All products and company names mentioned in this document may be the trademarks of their respective holders. Page 22 of 22 Not Recommended for New Designs Products