hd64338023s Renesas Electronics Corporation., hd64338023s Datasheet - Page 117

• Manufacturer Part Number: hd64338023s
• Description: Renesas 8-bit Single-chip Microcomputer Super Low Power Series
• Manufacturer: Renesas Electronics Corporation.

3.1
Exception handling is performed in the H8/38024 Group, H8/38024S Group, H8/38024F-ZTAT
Group, and H8/38124 Group when a reset or interrupt occurs. Table 3.1 shows the priorities of
these two types of exception handling.
Table 3.1
Priority
High
Low
3.2
3.2.1
A reset is the highest-priority exception. The internal state of the CPU and the registers of the on-
chip peripheral modules are initialized.
3.2.2
As soon as the
To make sure the chip is reset properly, observe the following precautions.
• At power on: Hold the
• Resetting during operation: Hold the
Reset exception handling takes place as follows.
• The CPU internal state and the registers of on-chip peripheral modules are initialized, with the
• The PC is loaded from the reset exception handling vector address (H'0000 to H'0001), after
I bit of the condition code register (CCR) set to 1.
which the program starts executing from the address indicated in PC.
Overview
Reset
Overview
Reset Sequence
Exception Source
Reset
Interrupt
Exception Handling Types and Priorities
R E S
pin goes low, all processing is stopped and the chip enters the reset state.
Section 3 Exception Handling
R E S
pin low until the clock pulse generator output stabilizes.
Time of Start of Exception Handling
Exception handling starts as soon as the reset state is cleared
When an interrupt is requested, exception handling starts after
execution of the present instruction or the exception handling in
progress is completed
R E S
pin low for at least 10 system clock cycles.
Rev. 7.00 Mar 10, 2005 page 75 of 652
Section 3 Exception Handling
REJ09B0042-0700