HD6412240 RENESAS [Renesas Technology Corp], HD6412240 Datasheet - Page 140

• Manufacturer Part Number: HD6412240
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 4 Exception Handling
4.2.4
If an interrupt is accepted after a reset but before the stack pointer (SP) is initialized, the PC and
CCR will not be saved correctly, leading to a program crash. To prevent this, all interrupt requests,
including NMI, are disabled immediately after a reset. Since the first instruction of a program is
always executed immediately after the reset state ends, make sure that this instruction initializes
the stack pointer (example: MOV.L #xx: 32, SP).
4.2.5
After reset release, MSTPCR is initialized to H'3FFF and all modules except the DTC enter
module stop mode. Consequently, on-chip supporting module registers cannot be read or written
to. Register reading and writing is enabled when module stop mode is exited.
Rev.3.00 Mar. 26, 2007 Page 98 of 772
REJ09B0355-0300
Interrupts after Reset
State of On-Chip Supporting Modules after Reset Release
RES
Address bus
RD
HWR, LWR
D
(1) (3) Reset exception handling vector address ((1) = H'000000, (3) = H'000002)
(2) (4) Start address (contents of reset exception handling vector address)
(5)
(6)
Note: * 3 program wait states are inserted.
15
to D
Start address ((5) = (2) (4))
First program instruction
0
Figure 4.3 Reset Sequence (Mode 4)
*
(1)
Vector fetch
(2)
High
*
(3)
Internal
processing
(4)
Fetch of first
program instruction
(5)
*
(6)