HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 793

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

• The contents of the CPU’s internal general registers are undefined at this time, so these
• Initial settings must also be made for the other on-chip registers.
• Boot mode can be entered by making the pin settings shown in table 19.9 and executing a
• Boot mode can be cleared by driving the reset pin low, waiting at least 20 states, then setting
• Do not change the mode pin input levels in boot mode.
• If the mode pin input levels are changed (for example, from low to high) during a reset, the
Notes: 1. Mode pins input must satisfy the mode programming setup time (t
19.6.2
When set to user program mode, the chip can program and erase its flash memory by executing a
user program/erase control program. Therefore, on-board reprogramming of the on-chip flash
memory can be carried out by providing on-board means supply of programming data, and storing
a program/erase control program in part of the program area if necessary.
To select user program mode, select a mode that enables the on-chip flash memory (mode 6 or 7).
In this mode, on-chip supporting modules other than flash memory operate as they normally
would in modes 6 and 7.
The flash memory itself cannot be read while the SWE bit is set to 1 to perform programming or
erasing, so the control program that performs programming and erasing should be run in on-chip
RAM or external memory. When the program is located in external memory, an instruction for
programming the flash memory and the following instruction should be located in on-chip RAM.
registers must be initialized immediately after branching to the programming control program.
In particular, since the stack pointer (SP) is used implicitly in subroutine calls, etc., a stack area
must be specified for use by the programming control program.
reset-start.
the mode pins, and executing reset release *
overflow reset.
state of ports with multiplexed address functions and bus control output pins (AS, RD, HWR)
will change according to the change in the microcomputer’s operating mode *
Therefore, care must be taken to make pin settings to prevent these pins from becoming output
signal pins during a reset, or to prevent collision with signals outside the microcomputer.
2. See section 9, I/O Ports.
User Program Mode
respect to the reset release timing.
1
. Boot mode can also be cleared by a WDT
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Section 19 ROM
= 200 ns) with
.