H8SLASH3021 datasheet(492/712 Pages) RENESAS

492 / 712 page

15. ROM

Rev.2.00 Mar. 22, 2007 Page 468 of 684

REJ09B0352-0200

On-Chip RAM Area Divisions in Boot Mode: In boot mode, the RAM area is divided into an

area used by the boot program and an area to which the programming control program is

transferred via the SCI, as shown in figure 15.8. The boot program area cannot be used until the

execution state in boot mode switches to the programming control program transferred from the

host.

H'FFDF10

H'FFE710

H'FFFF0F

Boot program

area

Programming

control program

area

Note: The boot program area cannot be used until the programming control program transferred to

RAM switches to the execution state. Note also that the boot program remains in this area

in RAM even after control branches to the programming control program.

Figure 15.8 RAM Areas in Boot Mode (Mode 6)

Notes on Use of Boot Mode

1. When the H8/3022 comes out of reset in boot mode, it measures the low period of the input at

the SCI’s RXD

1 pin.

The reset should end with RXD

1 high.

After the reset ends, it takes about

100 states for the H8/3022 to get ready to measure the low period of the RXD

1 input.

2. In boot mode, if any data has been programmed into the flash memory (if all data is not H'FF),

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.

3. Interrupts cannot be used while the flash memory is being programmed or erased.

4. The RXD

1 and TXD1 lines should be pulled up on the board.

5. Before branching to the programming control program (in mode 6, H'FFE710 in the RAM

area), the H8/3022 terminates transmit and receive operations by the on-chip SCI (channel 1)

(by clearing the RE and TE bits to 0 in the serial control register (SCR)), but the adjusted bit

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