Section 20 Rom; Features - Hitachi H8S/2646 Hardware Manual

20.1

Features

The LSI (H8S/2646R, H8S/2648R) has 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. Block erase (in single-block units) can
be performed. To erase the entire flash memory, each block must be erased in turn. Block
erasing can be performed as required on 1 kB, 8 kB, 16 kB, 28 kB, and 32 kB blocks.
• Programming/erase times
The flash memory programming time is 10 ms (typ.) for simultaneous 128-byte programming,
equivalent to 78 µs (typ.) per byte, and the erase time is 100 ms (typ.).
• 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 LSI's bit rate can be automatically adjusted to match the
transfer bit rate of the host.
• Flash memory emulation in RAM
Flash memory programming can be emulated in real time by overlapping a part of RAM onto
flash memory.
• Protect modes
There are two protect modes, hardware and software, 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.

Section 20 ROM

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