Datasheet

Rev.6.00 Oct.28.2004 page 574 of 1016
REJ09B0138-0600H
19.6 Overview of Flash Memory (H8S/2357 F-ZTAT)
19.6.1 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/2357 Group chip can be automatically adjusted to match the
transfer bit rate of the host.
• 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.
• Programmer mode
Flash memory can be programmed/erased in programmer mode, using a PROM programmer, as well as in on-board
programming mode.