SUMMARY DESCRIPTION
The M29W400B is a 4 Mbit (512Kb x8 or 256Kb x16) non-volatile memory that can be read, erased and reprogrammed. These operations can be performed using a single low voltage (2.7 to 3.6V) supply. On power-up the memory defaults to its Read mode where it can be read in the same way as a ROM or EPROM. The M29W400B is fully backward compatible with the M29W400.

■ SINGLE 2.7 to 3.6V SUPPLY VOLTAGE for PROGRAM, ERASE and READ OPERATIONS
■ ACCESS TIME: 55ns
■ PROGRAMMING TIME
   – 10µs per Byte/Word typical
■ 11 MEMORY BLOCKS
   – 1 Boot Block (Top or Bottom Location)
   – 2 Parameter and 8 Main Blocks
■ PROGRAM/ERASE CONTROLLER
   – Embedded Byte/Word Program algorithm
   – Embedded Multi-Block/Chip Erase algorithm
   – Status Register Polling and Toggle Bits
   – Ready/Busy Output Pin
■ ERASE SUSPEND and RESUME MODES
   – Read and Program another Block during Erase Suspend
■ UNLOCK BYPASS PROGRAM COMMAND
   – Faster Production/Batch Programming
■ TEMPORARY BLOCK UNPROTECTION MODE
■ LOW POWER CONSUMPTION
   – Standby and Automatic Standby
■ 100,000 PROGRAM/ERASE CYCLES per BLOCK
■ 20 YEARS DATA RETENTION
   – Defectivity below 1 ppm/year
■ ELECTRONIC SIGNATURE
   – Manufacturer Code: 0020h
   – Top Device Code M29W400BT: 00EEh
   – Bottom Device Code M29W400BB: 00EFh