The TMS320F28P65x MCU products have a common
architectural definition of operating states. These operating states should be observed by
the system developer in their software and system level design concepts. The operating
states state machine is shown in Figure 4-9. The operating states can be classified into device boot phase and CPU1SS operation phase
(applicable to all the devices), and CPU2SS operation phase (applicable to TMS320F28P65xD
class of devices). CPU2SS operation phase is initiated by CPU1SS operation phase. Any
critical errors in either CPU1SS operation phase or CPU2SS operation phase cause the device
to enter into safe state.
The various states of the device operating states state machine are:
- Powered Off: This is the initial operating
state of C2000 MCU. No power is applied to either core or I/O power supply and the device
is non-functional. An external supervisor can perform this action (power-down the C2000
MCU) in any of the C2000 MCU states as response to a system level fault condition or a
fault condition indicated by the C2000 MCU.
- Reset State: In this state, the device
reset is asserted either using the external pins or using any of the internal
sources.
- Safe State: In the Safe state, the device
is either not performing any functional operations or an internal fault condition is
indicated using the device I/O pins.
- Cold Boot: In the cold boot state, the CPU
remains powered but in reset. When the cold boot process is completed, the reset of the
master CPU is internally released, leading to the warm boot stage.
- Warm Boot: The CPU begins execution from
Boot ROM during the warm boot stage. CPU initializes the device security (all memories
come up as secure at the beginning of the warm boot and this stage configures the security
as needed for the particular system), exception handling and calibration of analog
components and initializes the peripheral boot mode if required. For more details
regarding boot process, see the device-specific boot ROM specification.
- Pre-operational: Transfer of control from
boot code to customer code takes place during this phase. Application-specific
configurations (for example, clock frequency, peripheral enable, pin mux, and so forth)
are performed in this phase. Boot time self-test/proof-test required to ensure proper
device operation is performed during this phase. See Section 6.4.4.8 (ROM8) for details.
- Operational: This marks the system exiting
the pre-operational state and entering the functional state. The device is capable of
supporting safety critical functionality during operational mode.
The device start-up timeline for both the CPUs are
shown in Figure 4-10.