Specifications

11
Memory
FLASH
A traditional strength of Hitachi’s
microcontrollers are the large integrated
memories and the advanced memory
technology.
Already for many years, it has been an
important strategy to provide
microcontrollers with high-speed,on-
chip Flash memory to the European
market, always at the leading edge of this
industry trend. This technology is now
offered in its third generation,providing
larger memory sizes and single-voltage
programming. Hitachi is currently
shipping over 4M Flash microcontrollers
per month.
A table in the middle of this brochure
shows Hitachi’s 16-bit microcontrollers
by ROM and RAM size,including 16
on-chip Flash derivatives.Please use the
table to select the devices which meet
your memory requirements.
Hundreds of customers worldwide have
taken advantage of our flash based
microcontrollers in their designs,about
one third in industrial and automotive
applications,approximately one fourth
each in consumer and office automation
and the remainder in telecommunications.
Integrating large and flexible memories
has numerous benefits for our customers,
some of which are becoming crucial in
today’s demanding electronics industry.
For example:Switching an older
microcontroller design,which uses
external memory and peripherals, to a
single-chip design,will drastically reduce
radiation,because the address and data
busses are a major source of radiation in
a system. Together with the low power
consumption of Hitachi’s microcontrollers,
such a redesign will often immediately
eliminate radiation problems. At the
same time costly shielding measures may
become unnecessary, thus lowering
system cost and board space requirements
will become less.
Other benefits of large integrated
memory and especially of on-chip Flash
memory are:
• end of line programming allows
flexibility in the software until
shipment
• allows easy and fast update in the field
without the need to open the
equipment
• allows software updates even remotely,
e. g. via modem/phone line
• fast response to changing customer
requirements
• non volatile storage of data and
parameters
• full availability of all ports, if external
busses can be avoided
• full speed operation,often impossible
or expensive if external memory is
used
Flash programming
• BOOT Mode
Boot mode is entered if the mode
pins of a H8/H8S are in a certain
state after reset. In boot mode
program execution starts from a
hidden ROM. The software in this
ROM initialises one of the serial
interfaces, downloads another piece of
software (available from Hitachi, if
desired),which then allows to
(re)programme the Flash memory.
Boot mode can be used to supply a
blank (i.e. new) Flash device with a
software,even when the device is
already soldered onto the PCB.
• USER Mode
User mode is not entered via reset. It
is fundamentally just like normal
operation,but with Flash
programming enabled via the mode
(usually FWE) pins.
In user mode, an external trigger
event causes the user software to copy
a piece of code into RAM. Program
execution then jumps to this code.
The Flash can then be reprogrammed
under the control of the user’s
application,using all the resources of
the chip (i.e. downloading the new
code does not necessarily have to use
a serial interface,but could use any
other resource). This mode is
intended for Flash memory updates.
• PROM Mode
All H8/H8S Flash derivatives can also
be programmed using general purpose
programming equipment, i.e. in the
same way OTP’s are programmed.