Datasheet

Section 17 ROM
Rev.7.00 Feb. 14, 2007 page 571 of 1108
REJ09B0089-0700
17.4 Overview of Flash Memory (H8S/2318 F-ZTAT, H8S/2317 F-ZTAT,
H8S/2315 F-ZTAT, H8S/2314 F-ZTAT)
17.4.1 Features
The H8S/2318 F-ZTAT, H8S/2317 F-ZTAT, H8S/2315 F-ZTAT, and H8S/2314 F-ZTAT have
384, 256, 128 kbytes of on-chip flash memory. 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 128 bytes at a time. Erasing is performed by block erase (in
single-block units). To erase the entire flash memory, the individual blocks must be erased
sequentially. Block erasing can be performed as required on 4-kbyte, 32-kbyte, and 64-kbyte
blocks.
• Programming/erase times
The flash memory programming time is 10.0 ms (typ.) for simultaneous 128-byte
programming, equivalent to 78 μs (typ.) per byte, and the erase time is 50 ms (typ.).
• Reprogramming capability
The flash memory can be reprogrammed a minimum of 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 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.