H8S-2350 RENESAS [Renesas Technology Corp], H8S-2350 Datasheet - Page 118

• Manufacturer Part Number: H8S-2350
• Description: 16-Bit Single-Chip Microcomputer
• 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 DMAC and 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 Sep 15, 2006 page 84 of 988
REJ09B0330-0300
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
Interrupts after Reset
State of On-Chip Supporting Modules after Reset Release
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)
Prefetch of first
program instruction
(5)
*
(6)