GENERAL DESCRIPTION
The MT28F004B3 (x8) and MT28F400B3 (x16/x8) are nonvolatile,
electrically block-erasable (flash), programmable memory devices
containing 4,194,304 bits organized as 262,144 words (16 bits) or
524,288 bytes (8 bits). Writing or erasing the device is done with
either a 3.3V or 5V VPP voltage, while all operations are performed
with a 3.3V VCC. Due to process technology advances, 5V VPP is
optimal for application and production programming. These devices
are fabricated with Micron’s advanced 0.18µm CMOS floating-gate
process.
The MT28F004B3 and MT28F400B3 are organized into seven separately
erasable blocks. To ensure that critical firmware is protected from
accidental erasure or overwrite, the devices feature a
hardware-protected boot block. Writing or erasing the boot block
requires either applying a super-voltage to the RP# pin or driving
WP# HIGH in addition to executing the normal write or erase
sequences. This block may be used to store code implemented in
low-level system recovery. The remaining blocks vary in density and
are written and erased with no additional security measures.
FEATURES
• Seven erase blocks:
16KB/8K-word boot block (protected)
Two 8KB/4K-word parameter blocks
Four main memory blocks
• Smart 3 technology (B3):
3.3V ±0.3V VCC
3.3V ±0.3V VPP application programming
5V ±10% VPP application/production programming1
• Compatible with 0.3µm Smart 3 device
• Advanced 0.18µm CMOS floating-gate process
• Address access time: 80ns
• 100,000 ERASE cycles
• Industry-standard pinouts
• Inputs and outputs are fully TTL-compatible
• Automated write and erase algorithm
• Two-cycle WRITE/ERASE sequence
• Byte- or word-wide READ and WRITE
(MT28F400B3, 256K x 16/512K x 8)
• Byte-wide READ and WRITE only
(MT28F004B3, 512K x 8)
• TSOP and SOP packaging options