HD6432345 Datasheet, PDF (563/907 Pages) Hitachi Semiconductor – H8S/2345 F-ZTAT Hardware Manual

17.6 Overview of Flash Memory
17.6.1 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 multiple 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 (5 V version)
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
With data transfer in boot mode, the bit rate of the H8S/2345 Series chip can be automatically
adjusted to match the transfer bit rate of the host. (9600 bps, 4800 bps)
• Flash memory emulation by RAM
Part of the RAM area can be overlapped onto flash memory, to emulate flash memory updates
in real time.
• 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.
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