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Section 2 CPU
R01UH0134EJ0400 Rev. 4.00 Page 93 of 2108
Sep 24, 2014
SH7262 Group, SH7264 Group
(1) Reset State
In the reset state, the CPU is reset. There are two kinds of reset, power-on reset and manual reset.
(2) Exception Handling State
The exception handling state is a transient state that occurs when exception handling sources such
as resets or interrupts alter the CPU’s processing state flow.
For a reset, the initial values of the program counter (PC) (execution start address) and stack
pointer (SP) are fetched from the exception handling vector table and stored; the CPU then
branches to the execution start address and execution of the program begins.
For an interrupt, the stack pointer (SP) is accessed and the program counter (PC) and status
register (SR) are saved to the stack area. The exception service routine start address is fetched
from the exception handling vector table; the CPU then branches to that address and the program
starts executing, thereby entering the program execution state.
(3) Program Execution State
In the program execution state, the CPU sequentially executes the program.
(4) Power-Down State
In the power-down state, the CPU stops operating to reduce power consumption. The SLEEP
instruction places the CPU in sleep mode, software standby mode, or deep standby mode.
(5) Bus-Released State
In the bus-released state, the CPU releases bus to a device that has requested it.