HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 792

• Manufacturer Part Number: HD6412320
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family H8S-2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 19 ROM
Notes on Use of Boot Mode
• When the chip comes out of reset in boot mode, it measures the low-level period of the input at
• In boot mode, if any data has been programmed into the flash memory (if all data is not 1), all
• 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'FF8400 to H'FFFBFF),
Rev.6.00 Sep. 27, 2007 Page 762 of 1268
REJ09B0220-0600
Note: * The boot program area cannot be used until a transition is made to the execution state
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.
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.
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).
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 19.12 RAM Areas in Boot Mode
H'FF7C00
H'FF83FF
H'FFFBFF
control program
Boot program
Programming
(30 kbytes)
(2 kbytes)
area*
area