Preliminary Datasheet MB85RS4MTY (Fujitsu) - 6

MB85RS4MTY STATUS REGISTER Bit No. Bit Name Function
Status Register Write Protect This is a bit composed of nonvolatile memories (FRAM). WPEN protects 7 WPEN writing to a status register (refer to “ WRITING PROTECT”) relating with WP input. Writing with the WRSR command and reading with the RDSR command are possible. Not Used Bits These are bits composed of nonvolatile memories, writing with the WRSR 6 to 4  command is possible. These bits are not used but they are read with the RDSR command. Block Protect 3 BP1 This is a bit composed of nonvolatile memory. This defines size of write protect block for the WRITE command (refer to “ BLOCK PROTECT”). Writing with the WRSR command and reading with the RDSR command 2 BP0 are possible. Write Enable Latch This indicates FRAM Array and status register are writable. The WREN command is for setting, and the WRDI command is for resetting. With the RDSR command, reading is possible but writing is not possible with the WRSR command. WEL is reset after the following operations. After power ON. After WRDI command recognition. After return from DPD mode. 1 WEL After return from Hibernate mode. After release from reset. Achieving continuous writing mode, WEL is not reset after following oper- ations making it possible to execute writing commands continuously. After WRSR command recognition. After WRITE command recognition. After WRSN command recognition. After SSWR command recognition. 0 0 This is a bit fixed to “0”. 6 DS501-00065-0v1-E Document Outline DESCRIPTION FEATURES PIN ASSIGNMENT PIN FUNCTIONAL DESCRIPTIONS BLOCK DIAGRAM SPI MODE SERIAL PERIPHERAL INTERFACE (SPI) STATUS REGISTER OP-CODE COMMAND BLOCK PROTECT WRITING PROTECT ABSOLUTE MAXIMUM RATINGS RECOMMENDED OPERATING CONDITIONS ELECTRICAL CHARACTERISTICS 1. DC Characteristics 2. AC Characteristics 3. Pin Capacitance TIMING DIAGRAM POWER ON/OFF SEQUENCE FRAM CHARACTERISTICS NOTE ON USE ESD AND LATCH-UP REFLOW CONDITIONS AND FLOOR LIFE Current status on Contained Restricted Substances ORDERING INFORMATION PACKAGE DIMENSION MARKING (Example) PACKING INFORMATION 1. Tube 2. Emboss Tape