The TMS320F2837xD/S and TMS320F2807x 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 4-10. 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 TMS320F2837xD 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, key analog
elements, digital control logic, and debug logic are initialized. 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, pinmux, 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 6.4.8 (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 4-11.