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8.2
Overview of Flash Memory
8.2.1
Features
The features of the flash memory are summarized below.
• Four flash memory operating modes
— Program mode
— Erase mode
— Program-verify mode
— Erase-verify mode
• Programming/erase methods
The flash memory is programmed 32 bytes at a time. Erasing is performed by block erase
(in single-block units). When erasing all blocks, the individual blocks must be erased
sequentially. Block erasing can be performed as required on 1-kbyte, 8-kbyte, 16-kbyte, 28-
kbyte, and 32-kbyte blocks.
• Programming/erase times
The flash memory programming time is 10 ms (typ.) for simultaneous 32-byte programming,
equivalent to 300 µs (typ.) per byte, and the erase time is 100 ms (typ.) per block.
• Reprogramming capability
The flash memory can be reprogrammed up to 100 times.
• On-board programming modes
There are two modes in which flash memory can be programmed/erased/verified on-board:
— Boot mode
— User program mode
• Automatic bit rate adjustment
If data transfer on boot mode, automatic adjustment is possible at host transfer bit rates and
MCU's bit rates.
• Protect modes
There are three protect modes, hardware, software, and error protect, which allow protected
status to be designated for flash memory program/erase/verify operations.
• Programmer mode
Flash memory can be programmed/erased in programmer mode, using a PROM programmer,
as well as in on-board programming mode.
Rev. 2.0, 11/00, page 172 of 1037
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