SH7261 Datasheet, PDF (135/1348 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7260 Series

Section 5 Exception Handling
(2) Power-On Reset by Means of H-UDI Reset Assert Command
When the H-UDI reset assert command is set, this LSI enters the power-on reset state. Power-on
reset by means of an H-UDI reset assert command is equivalent to power-on reset by means of the
RES pin. Setting the H-UDI reset negate command cancels the power-on reset state. The time
required between an H-UDI reset assert command and H-UDI reset negate command is the same
as the time to keep the RES pin low to initiate a power-on reset. In the power-on reset state
generated by an H-UDI reset assert command, setting the H-UDI reset negate command starts
power-on reset exception handling. The CPU operates in the same way as when a power-on reset
was caused by the RES pin.
(3) Power-On Reset Initiated by WDT
When a setting is made for a power-on reset to be generated in the WDT’s watchdog timer mode,
and WTCNT of the WDT overflows, this LSI enters the power-on reset state.
In this case, WRCSR of the WDT and FRQCR of the CPG are not initialized by the reset signal
generated by the WDT.
If a reset caused by the RES pin or the H-UDI reset assert command occurs simultaneously with a
reset caused by WDT overflow, the reset caused by the RES pin or the H-UDI reset assert
command has priority, and the WOVF bit in WRCSR is cleared to 0. When power-on reset
exception processing is started by the WDT, the CPU operates in the same way as when a power-
on reset was caused by the RES pin.
Rev. 2.00 Sep. 07, 2007 Page 103 of 1312
REJ09B0320-0200