HD6432345 Datasheet, PDF (584/907 Pages) Hitachi Semiconductor – H8S/2345 F-ZTAT Hardware Manual

H'FFEC00
Boot program
area*
(2 kbytes)
H'FFF3FF
H'FFF400
Programming
control program
area
(2 kbytes)
H'FFFBFF
On chip RAM (4 kbytes)
Note: * The boot program area cannot be used until a transition is made to the execution state
for the programming control program transferred to RAM. Note that the boot program
remains stored in this area after a branch is made to the programming control program.
Figure 17.18 RAM Areas in Boot Mode
Notes on Use of User Mode:
• When the chip comes out of reset in boot mode, it measures the low-level period of the input at
the SCI’s RxD1 pin. The reset should end with RxD1 high. After the reset ends, it takes
approximately 100 states before the chip is ready to measure the low-level period of the RxD1
pin.
• In boot mode, if any data has been programmed into the flash memory (if all data is not 1), all
flash memory blocks are erased. Boot mode is for use when user program mode is unavailable,
such as the first time on-board programming is performed, or if the program activated in user
program mode is accidentally erased.
• Interrupts cannot be used while the flash memory is being programmed or erased.
• The RxD1 and TxD1 pins should be pulled up on the board.
• Before branching to the programming control program (RAM area H'FFF400), the chip
terminates transmit and receive operations by the on-chip SCI (channel 1) (by clearing the RE
and TE bits in SCR to 0), but the adjusted bit rate value remains set in BRR. The transmit data
output pin, TxD1, goes to the high-level output state (P31DDR = 1, P31DR = 1).
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