CY14B256Q1

CY14B256Q2

CY14B256Q3

Document Number: 001-53882 Rev. *E

Page 2 of 26

Contents

Pinouts .............................................................................. 3

Device Operation .............................................................. 4

SRAM Write................................................................. 4

SRAM Read ................................................................ 4

STORE Operation ....................................................... 5

AutoStore Operation .................................................... 5

Software STORE Operation ........................................ 5

Hardware STORE and HSB Pin Operation ................. 5

RECALL Operation ...................................................... 6

Hardware RECALL (Power-Up) .................................. 6

Software RECALL ....................................................... 6

Disabling and Enabling AutoStore ............................... 6

Noise Considerations ....................................................... 6

Serial Peripheral Interface ............................................... 6

SPI Overview............................................................... 6

SPI Modes ................................................................... 8

SPI Operating Features.................................................... 9

Power-Up .................................................................... 9

Power On Reset .......................................................... 9

Power-Down................................................................ 9

Active Power and Standby Power Modes ................... 9

SPI Functional Description .............................................. 9

Status Register ............................................................... 10

Read Status Register (RDSR) Instruction ................. 10

Write Status Register (WRSR) Instruction ................ 10

Write Protection and Block Protection ......................... 11

Write Enable (WREN) Instruction .............................. 11

Write Disable (WRDI) Instruction .............................. 11

Block Protection ........................................................ 11

Write Protect (WP) Pin .............................................. 12

Memory Access .............................................................. 12

Read Sequence (READ) instruction .......................... 12

Write Sequence (WRITE) instruction ........................ 12

nvSRAM Special Instructions ........................................ 13

Software STORE (STORE) instruction ...................... 13

Software RECALL (RECALL) instruction .................. 14

AutoStore Enable (ASENB) instruction ..................... 14

AutoStore Disable (ASDISB) instruction ................... 14

HOLD Pin Operation ................................................. 14

Best Practices ................................................................. 15

Maximum Ratings ........................................................... 16

DC Electrical Characteristics ........................................ 16

Data Retention and Endurance ..................................... 17

Capacitance .................................................................... 17

Thermal Resistance ........................................................ 17

AC Test Conditions ........................................................ 17

AC Switching Characteristics ....................................... 18

AutoStore or Power-Up RECALL .................................. 19

Software Controlled STORE and RECALL Cycles ...... 20

Hardware STORE Cycle ................................................. 21

Ordering Information ...................................................... 22

Ordering Code Definition ........................................... 22

Package Diagrams .......................................................... 23

Acronyms........................................................................ 25

Document Conventions ................................................. 25

Document History Page ................................................. 26

Sales, Solutions, and Legal Information ...................... 27

Worldwide Sales and Design Support....................... 27

Products .................................................................... 27

PSoC Solutions ......................................................... 27

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