h8s-2628 Renesas Electronics Corporation., h8s-2628 Datasheet - Page 99

• Manufacturer Part Number: h8s-2628
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

4.3.2
If an interrupt is accepted immediately after a reset and 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 exception handling is
executed. Since the first instruction of a program is always executed immediately after the reset,
make sure that this instruction initializes the stack pointer (example: MOV.L #xx: 32, SP).
(1)(3) Reset exception handling vector address (when reset, (1)=H'000000, (3)=H'000002)
(2)(4) Start address (contents of reset exception handling vector address)
(5) Start address ((5)=(2)(4))
(6) First program instruction
Note: * Three program wait states are inserted.
RES
RD
HWR, LWR
D15 to D0
Address bus
Interrupts after Reset
(Advanced Mode with On-chip ROM Disabled: Not Available in this LSI)
Figure 4.2 Reset Sequence
(1)
*
Vector fetch
(2)
High
*
Rev. 3.00 Oct 04, 2005 page 59 of 598
(3)
(4)
Internal
processing
Section 4 Exception Handling
Fetch of first
program instruction
*
(5)
REJ09B0155-0300
(6)