SUMMARY DESCRIPTION
The M29W640D is a 64 Mbit (8Mb x8 or 4Mb 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.
The memory is divided into blocks that can be erased independently so it is possible to preserve valid data while old data is erased. Blocks can be protected in units of 256 KByte (generally groups of four 64 KByte blocks), to prevent accidental Program or Erase commands from modifying the memory. Program and Erase commands are written to the Command Interface of the memory. An on-chip Program/Erase Controller simplifies the process of programming or erasing the memory by taking care of all of the special operations that are required to update the memory contents. The end of a program or erase operation can be detected and any error conditions identified. The command set required to control the memory is consistent with JEDEC standards.

FEATURES SUMMARY
■ SUPPLY VOLTAGE
   – VCC = 2.7V to 3.6V for Program, Erase, Read
   – VPP =12 V for Fast Program (optional)
■ ACCESS TIME: 70, 90 ns
■ PROGRAMMING TIME
   – 10 µs per Byte/Word typical
   – Double Word Programming Option
■ 135 MEMORY BLOCKS
   – 1 Boot Block and 7 Parameter Blocks, 8 KBytes each (Top or Bottom Location)
   – 127 Main Blocks, 64 KBytes each
■ PROGRAM/ERASE CONTROLLER
   – Embedded Byte/Word Program algorithms
■ ERASE SUSPEND and RESUME MODES
   – Read and Program another Block during Erase Suspend
■ UNLOCK BYPASS PROGRAM COMMAND
   – Faster Production/Batch Programming
■ VPP/WP Pin for FAST PROGRAM and WRITE PROTECT
■ TEMPORARY BLOCK UNPROTECTION MODE
■ COMMON FLASH INTERFACE
   – 64-bit Security Code
■ EXTENDED MEMORY BLOCK
   – Extra block used as security block or to store additional information
■ LOW POWER CONSUMPTION
   – Standby and Automatic Standby
■ 100,000 PROGRAM/ERASE CYCLES per BLOCK
■ ELECTRONIC SIGNATURE
   – Manufacturer Code: 0020h
   – Top Device Code M29W640DT: 22DEh
   – Bottom Device Code M29W640DB: 22DFh