Datasheet

Section 22 Flash Memory
Page 1170 of 1408 R01UH0309EJ0500 Rev. 5.00
Sep 24, 2012
H8S/2456, H8S/2456R, H8S/2454 Group
4. After all user ROMs are automatically erased, the state of waiting for programming/erasing
command is entered. When the programming command is received, the state shifts to the state
of waiting for programming data. The same applies to erasing. In addition to the commands
for programming/erasing, there are commands for performing sum check, blank check
(erasure check), and memory read of the user ROM, and acquiring the current status
information.
(3) Notes on USB Boot Mode Execution
• The clock of 48 MHz needs to be supplied to the USB module. Set the external clock
frequency and clock pulse generator so as to supply 48 MHz as the clock for the USB (cku).
For details, refer to section 23, Clock Pulse Generator.
• Use the P20 pin for the D+ pull-up control connection.
• For the stable supply of the power during the flash memory programming and erasing, the
cable should not be connected via the bus powered HUB.
• If the bus powered HUB is disconnected during the flash memory programming and erasing,
permanent damage to the LSI may result.
• If the USB bus in the bus power mode enters the suspend mode, this does not make the
transition to the software standby mode of the power-down mode.