Datasheet

Section 23 ROM (H8S/2148 F-ZTAT A-Mask Version, H8S/2147 F-ZTAT A-Mask Version, H8S/2144 F-ZTAT A-Mask Version)
Rev. 4.00 Sep 27, 2006 page 688 of 1130
REJ09B0327-0400
23.4 Overview of Flash Memory
23.4.1 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 128 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, 28-kbyte, 16-kbyte, 8-
kbyte, and 32-kbyte blocks.
• Programming/erase times
The flash memory programming time is 10 ms (typ.) for simultaneous 128-byte programming,
equivalent to approximately 80 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 chip can be automatically adjusted to match
the transfer bit rate of the host.
• 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.