Section 24 ROM
Rev. 3.00 Jan 25, 2006 page 728 of 872
REJ09B0286-0300
24.7.1
Boot Mode
Table 24.5 shows the boot mode operations between reset end and branching to the programming
control program.
1. When boot mode is used, the flash memory programming control program must be prepared in
the host beforehand. Prepare a programming control program in accordance with the
description in section 24.8, Flash Memory Programming/Erasing. In boot mode, if any data
exists in the flash memory (except in the case that all data are 1), all blocks in the flash
memory are erased. Use boot mode at initial writing in the on-board state, or forced recovery
when user program mode cannot be executed because the program to be initiated in user
program mode was mistakenly erased.
2. The SCI_1 should be set to asynchronous mode, and the transfer format as follows: 8-bit data,
1 stop bit, and no parity.
3. When the boot program is initiated, this LSI measures the low-level period of asynchronous
SCI communication data (H'00) transmitted continuously from the host. This LSI then
calculates the bit rate of transmission from the host, and adjusts the SCI_1 bit rate to match
that of the host. The reset should end with the RxD1 pin high. The RxD1 and TxD1 pins
should be pulled up on the board if necessary. After the reset ends, it takes approximately 100
states before this LSI is ready to measure the low-level period.
4. After matching the bit rates, this LSI transmits one H'00 byte to the host to indicate the end of
bit rate adjustment. The host should confirm that this adjustment end indication (H'00) has
been received normally, and transmit one H'55 byte to this LSI. If reception could not be
performed normally, initiate boot mode again by a reset. Depending on the host’s transfer bit
rate and system clock frequency of this LSI, there will be a discrepancy between the bit rates
of the host and this LSI. To operate the SCI properly, set the host’s transfer bit rate and system
clock frequency of this LSI within the ranges listed in table 24.6.
5. In boot mode, a part of the on-chip RAM area is used by the boot program. Addresses
H'FF0800 to H'FF1FFF is the area to which the programming control program is transferred
from the host. Note, however, that ID codes are assigned to addresses H'FF0800 to H'FF0807.
The boot program area cannot be used until the execution state in boot mode switches to the
programming control program. Figure 24.6 shows the on-chip RAM area in boot mode.
6. Before branching to the programming control program (H'FF0808 in the RAM area), this LSI
terminates transfer operations by the SCI_1 (by clearing the RE and TE bits in SCR to 0), but
the adjusted bit rate value remains set in BRR. Therefore, the programming control program
can still use it for transfer of write data or verify data with the host. The TxD1 pin is in high-
level output state. The contents of the CPU general registers are undefined immediately after
Содержание H8S/2158
Страница 10: ...Rev 3 00 Jan 25 2006 page viii of lii...
Страница 36: ...Rev 3 00 Jan 25 2006 page xxxiv of lii B Product Lineup 863 C Package Dimensions 864 Index 865...
Страница 47: ...Rev 3 00 Jan 25 2006 page xlv of lii Appendix Figure C 1 Package Dimensions TBP 112A 864...
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Страница 70: ...Section 1 Overview Rev 3 00 Jan 25 2006 page 16 of 872 REJ09B0286 0300...
Страница 118: ...Section 3 MCU Operating Modes Rev 3 00 Jan 25 2006 page 64 of 872 REJ09B0286 0300...
Страница 126: ...Section 4 Exception Handling Rev 3 00 Jan 25 2006 page 72 of 872 REJ09B0286 0300...
Страница 198: ...Section 6 Bus Controller Rev 3 00 Jan 25 2006 page 144 of 872 REJ09B0286 0300...
Страница 326: ...Section 10 8 Bit PWM Timer PWM Rev 3 00 Jan 25 2006 page 272 of 872 REJ09B0286 0300...
Страница 440: ...Section 15 Watchdog Timer WDT Rev 3 00 Jan 25 2006 page 386 of 872 REJ09B0286 0300...
Страница 606: ...Section 17 I 2 C Bus Interface IIC Rev 3 00 Jan 25 2006 page 552 of 872 REJ09B0286 0300...
Страница 742: ...Section 19 Multimedia Card Interface MCIF Rev 3 00 Jan 25 2006 page 688 of 872 REJ09B0286 0300...
Страница 744: ...Section 20 Encryption Operation Circuit DES and GF Rev 3 00 Jan 25 2006 page 690 of 872 REJ09B0286 0300...
Страница 750: ...Section 21 D A Converter Rev 3 00 Jan 25 2006 page 696 of 872 REJ09B0286 0300...
Страница 768: ...Section 22 A D Converter Rev 3 00 Jan 25 2006 page 714 of 872 REJ09B0286 0300...
Страница 770: ...Section 23 RAM Rev 3 00 Jan 25 2006 page 716 of 872 REJ09B0286 0300...
Страница 824: ...Section 26 Clock Pulse Generator Rev 3 00 Jan 25 2006 page 770 of 872 REJ09B0286 0300...
Страница 844: ...Section 27 Power Down Modes Rev 3 00 Jan 25 2006 page 790 of 872 REJ09B0286 0300...
Страница 878: ...Section 28 List of Registers Rev 3 00 Jan 25 2006 page 824 of 872 REJ09B0286 0300...
Страница 926: ...Index Rev 3 00 Jan 25 2006 page 872 of 872 REJ09B0286 0300...