Datasheet

Section 7 ROM
Page 174 of 982 REJ09B0465-0300 Rev. 3.00
Sep 17, 2010
H8S/20103, H8S/20203, H8S/20223, H8S/20115, H8S/20215, H8S/20235 Group
1. After boot mode is initiated, this LSI adjusts the SCI3_1 bit rate so that it should match the
host's bit rate.
2. This LSI sends the requested information to the host in response to inquiries regarding the size,
configuration, and start addresses of the user ROM areas, information on the supported
devices, etc.
3. On receiving a programming/erasure state transition command, this LSI erases the entire user
ROM area automatically.
4. When completing erasure of the user ROM area, this LSI enters the programming/erasure-
command wait state. After transmission of the programming selection command, the host
should transmit the address at which the programming should start and the programming data.
When programming is completed, the host should transmit H'FFFFFFFF as the programming
start address to terminate programming. This allows this LSI to return to the
programming/erasure-command wait state from the programming-data wait state. If the above
programming-termination command is once issued to an area in an erasure block and when
that block is to be programmed again, erase the block before programming. Figure 7.5 shows
an example of an erasure block containing the area that has been already programmed.
On receiving an erasure selection command, this LSI enters the erasure-block-information wait
state. After transmission of the erasure selection command, the host should transmit the erasure
block number. When erasure is completed, the host should transmit H'FF as the erasure block
number. This allows this LSI to return to the programming/erasure-command wait state from
the erasure-block-information wait state. Note that erasure is necessary only when
programming is once done in boot mode and then only a specific block is to be reprogrammed
without applying a reset-start. If the necessary programming can be done in a single operation,
such erasure processing is unnecessary because all the blocks are erased before this LSI enters
the wait state for programming, erasure, or other commands. In addition to the
programming/erasure commands, there are commands for sum checking and blank checking
(erasure checking) of the user ROM areas, memory reading, and acquiring the current state
information.
Note that data can be read from the user ROM area only after the user ROM area has been
automatically erased and then programmed.