Datasheet

Table Of Contents
Section 4 Exception Handling
Page 76 of 846 REJ09B0140-0900 Rev. 9.00
Sep 16, 2010
H8S/2215 Group
A reset caused by the watchdog timer can also be of either of two types: a power-on reset or a
manual reset.
When the MRES pin is used, MRES pin input must be enabled by setting the MRESE bit to 1 in
SYSCR.
4.3.2 Reset Exception Handling
When the RES or MRES pin goes high after being held low for the necessary time, this LSI starts
reset exception handling as follows:
1. The internal state of the CPU and the registers of the on-chip peripheral modules are
initialized, the T bit is cleared to 0 in EXR, and the I bit is set to 1 in EXR and CCR.
2. The reset exception handling vector address is read and transferred to the PC, and program
execution starts from the address indicated by the PC.