Datasheet

Table Of Contents
Section 4 Exception Handling
Page 78 of 846 REJ09B0140-0900 Rev. 9.00
Sep 16, 2010
H8S/2215 Group
φ
RES, MRES
Internal address
bus
Internal read
signal
Internal write
signal
Internal data
bus
Vector fetch
(1)
(3) (5)
High
Internal
processing
Prefetch of
first program
instruction
(4) (6)(2)
(1) (3)
(2) (4)
(5)
(6)
Reset exception handling vector address (for power-on reset, (1) = H'000000,
(3) = H'000002; for manual reset, (1) = H'000004, (3) = H'000006)
Start address (contents of reset exception handling vector address)
Start address ((5) = (2) (4))
First program instruction
Figure 4.2 Reset Sequence (Modes 6, 7)
4.3.3 Interrupts after Reset
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 SP).
4.3.4 State of On-Chip Peripheral Modules after Reset Release
After reset release, MSTPCRA to MSTPCRC are initialized to H'3F, H'FF, and H'FF, respectively,
and all modules except the DMAC and DTC enter module stop mode. Consequently, on-chip
peripheral module registers cannot be read from or written to. Register reading and writing is
enabled when module stop mode is exited.