Hardware manual

Rev. 3.0, 09/98, page 44 of 361
2.6 CPU States
The CPU has three states: the program execution state, exception-handling state, and power-down
state. The power-down state is further divided into three modes: the sleep mode, software
standby mode, and hardware standby mode. Figure 2.11 summarizes these states, and figure 2.12
shows a map of the state transitions.
The CPU executes successive program instructions.
A transient state triggered by a reset or interrupt. The CPU executes
a hardware sequence that includes loading the program counter
from the vector table.
A state in which some or all of
the chip functions are stopped
to conserve power.
State Program execution state
Exception-handling state
Power-down state Sleep mode
Software standby mode
Hardware standby mode
Figure 2.11 Operating States