AN99199 S25FL1-K SPI Power-Up Timing and Reset AN99199 discusses the considerations for ensuring strict adherence to Power-Up Timing and Voltage Levels specified in the data sheet for Cypress S25FL1-K SPI Multi-I/O Flash Memory family devices. 1 Introduction The S25FL1-K Serial Peripheral Interface (SPI) Multi-I/O Flash Memory family requires strict adherence to PowerUp Timing and Voltage Levels specified in the data sheet. 2 Power-On (Cold) Reset S25FL1-K devices execute a Power-On Reset (POR) process until a time delay of tPUW has elapsed after the moment that VCC rises above the VWI threshold as shown in Figure 1. The device must not be selected until after tVSL since Chip Select (CS#) must to go high with VCC, i.e. no commands may be sent to the device until the end of tVSL. Program, Erase, and Write instructions will be ignored until after tPUW. Power-Up Timing and Voltage Level parameters are shown in Table 1. CS# should not be held low during the POR. Figure 1. Power-Up Timing and Voltage Levels VCC VCC (max) Program, Erase, and Write instructions are ignored CS# must track VCC VCC (min) t VSL Reset State Read instructions allowed Device is fully accessible VWI t PUW Time Table 1. Power-Up Timing and Voltage Levels Parameter Symbol Spec Min Max VCC (min) to CS# Low tVSL Power-Up to Write — Time Delay Before Write Command tPUW Write Inhibit Threshold Voltage VWI 2.4 V tPD 10.0 µs VCC Low 1.0 V Power-Down Time VCC Power-Down Reset Threshold Voltage 10 Unit µs 10 ms Note: 1. These parameters are characterized only. www.cypress.com Document No. 001-99199 Rev. *A 1 S25FL1-K SPI Power-Up Timing and Reset 3 Software Reset Command After a Power-On (Cold) Reset or Power-Down and Voltage Drop, issuing the Software Reset command is recommended as a best practice. The Software controlled Reset command restores the device to its initial power up state by reloading volatile registers from non-volatile default values. A Software Reset is initiated by the Software Reset Enable command (66h) followed by the Software Reset command (99h) and then executed when CS# is brought high after tRCH time at the end of the Software Reset instruction and requires an additional tRST time before executing the next Instruction after the Software Reset as shown in Figure 2 and Table 2. Figure 2. Software Reset Command Timing tCS2 tRST CS# SCLK tRCH SI 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 SO Phase Reset Enable Instructi on (66h) Reset Instruction (99h) Reset to Next Inst.. Table 2. Software Reset Timing Spec Parameter Symbol End of Reset Instruction to CE# High tRCH 40 ns CE# High to Next Instruction after Reset tRST 1.5 µs Min Max Unit If a Software Reset is initiated during a Erase, Program or Register write operation, the data in that Sector, Page, or Register is unknown, and the operation needs to be initiated again. When the device is in Deep Power Down mode, the software reset commands are ignored and have no effect. To reset the device send the Release Power down command (ABh) and after the time duration of CS# High to Standby Mode without Electronic Signature Read tRES1, the device will resume normal operation and the Software reset commands will be accepted. 4 Summary The Power-Up Timing and Voltage Levels specified in the S25FL1-K device family data sheet should be strictly adhered to during the Power-On Reset (POR) process, and, in particular, Chip Select CS# should not be held low during the POR. Furthermore, issuing the Software Reset command after the Power-On (Cold) Reset or PowerDown and Voltage Drop is recommended as a best practice. www.cypress.com Document No. 001-99199 Rev. *A 2 S25FL1-K SPI Power-Up Timing and Reset Document History Page Document Title: AN99199 - S25FL1-K SPI Power-Up Timing and Reset Document Number: 001-99199 Rev. ECN No. Orig. of Change 4929456 MSWI ** *A www.cypress.com Submission Date Description of Change 09/04/2014 Initial version 09/22/2015 Updated in Cypress template Document No. 001-99199 Rev. *A 3 S25FL1-K SPI Power-Up Timing and Reset Worldwide Sales and Design Support Worldwide Sales and Design Support Cypress maintains a worldwide network of offices, solution centers, manufacturers’ representatives, and distributors. To find the office closest to you, visit us at Cypress Locations. # 999 Products PSoC® Solutions Automotive..................................cypress.com/go/automotive psoc.cypress.com/solutions Clocks & Buffers ................................ cypress.com/go/clocks PSoC 1 | PSoC 3 | PSoC 4 | PSoC 5LP Interface......................................... cypress.com/go/interface Cypress Developer Community Lighting & Power Control ............cypress.com/go/powerpsoc Memory........................................... cypress.com/go/memory PSoC ....................................................cypress.com/go/psoc Touch Sensing .................................... cypress.com/go/touch Community | Forums | Blogs | Video | Training Technical Support cypress.com/go/support USB Controllers ....................................cypress.com/go/USB Wireless/RF .................................... cypress.com/go/wireless MirrorBit®, MirrorBit® Eclipse™, ORNAND™, EcoRAM™ and combinations thereof, are trademarks and registered trademarks of Cypress Semiconductor Corp. All other trademarks or registered trademarks referenced herein are the property of their respective owners. Cypress Semiconductor 198 Champion Court San Jose, CA 95134-1709 Phone: Fax: Website: 408-943-2600 408-943-4730 www.cypress.com © Cypress Semiconductor Corporation, 2014-2015. 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. This 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. www.cypress.com Document No. 001-99199 Rev. *A 4