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Section 15 ROM
15.1
Features
The H8/3022 Series has 256 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 4 kbytes, 32 kbytes, and 64 kbytes blocks.
•
Programming/erase times
The flash memory programming time is 10 ms (typ.) for simultaneous 128-byte programming,
equivalent to about 80
µ
s (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.
•
PROM mode
Flash memory can be programmed/erased in programmer mode, using a PROM programmer,
as well as in on-board PROM mode.