HD6417606 RENESAS [Renesas Technology Corp], HD6417606 Datasheet - Page 75

• Manufacturer Part Number: HD6417606
• Manufacturer: RENESAS [Renesas Technology Corp]

• Reset state
• Exception handling state
• Program execution state
• Power-down state
The CPU is reset. When the RES pin is driven low, the CPU enters the power-on reset state.
When the RES pin is high and MRES pin is low, the CPU enters the manual reset state.
This state is a transitional state in which the CPU processing state changes due to a request for
exception handling such as a reset or an interrupt.
When a reset occurs, the execution start address as the initial value of the program counter
(PC) and the initial value of the stack pointer (SP) are fetched from the exception handling
vector table. Then, a branch is made for the start address to execute a program.
When an interrupt occurs, the PC and status register (SR) are saved in the stack area pointed to
by SP. The start address of an exception handling routine is fetched from the exception
handling vector table and a branch to the address is made to execute a program.
Then the processing state enters the program execution state.
The CPU executes programs sequentially.
The CPU stops to reduce power consumption. The SLEEP instruction makes the CPU enter
sleep mode or software standby mode.
Rev. 4.00 Sep. 13, 2007 Page 49 of 502
REJ09B0239-0400
Section 2 CPU