ZHCSHE0 December 2017 TMS320F28377D-EP
The device boot ROM (on both the CPUs) contains bootloading software. The CPU1 boot ROM does the system initialization before bringing CPU2 out of reset. The device boot ROM is executed each time the device comes out of reset. Users can configure the device to boot to flash (using GET mode) or choose to boot the device through one of the bootable peripherals by configuring the boot mode GPIO pins.
The CPU1 boot ROM, being master, owns the boot mode GPIO and boot configurations. The CPU2 boot ROM either boots to flash (if configured to do so through user configurable DCSM OTP) or enters a WAIT BOOT mode if no OTP is programmed. In WAIT BOOT mode, the CPU1 application instructs the CPU2 boot ROM on how to boot further using boot mode IPC commands supported by CPU2 boot ROM.
Table 5-13 shows the possible boot modes supported on the device. The default boot mode pins are GPIO72 (boot mode pin 1) and GPIO 84 (boot mode pin 0). Users may choose to have weak pullups for boot mode pins if they use a peripheral on these pins as well, so the pullups can be overdriven. On this device, customers can change the factory default boot mode pins by programming user configurable DCSM OTP locations. This is recommended only for cases in which the factory default boot mode pins do not fit into the customer design. More details on the locations to be programmed is available in the TMS320F2837xD Dual-Core Delfino Microcontrollers Technical Reference Manual.
|MODE NO.||CPU1 BOOT MODE||CPU2 BOOT MODE||TRST||GPIO72|
|0||Parallel I/O||Boot from Master||0||0||0|
|1||SCI Mode||Boot from Master||0||0||1|
|2||Wait Boot Mode||Boot from master||0||1||0|
|3||Get Mode||Boot from Master||0||1||1|
|4-7||EMU Boot Mode (Emulator Connected)||Boot from Master||1||X||X|
The default behavior of Get mode is boot-to-flash. On unprogrammed devices, using Get mode will result in repeated watchdog resets, which may prevent proper JTAG connection and device initialization. Use Wait mode or another boot mode for unprogrammed devices.
Some reset sources are internally driven by the device. The user must ensure the pins used for boot mode are not actively driven by other devices in the system for these cases. The boot configuration has a provision for changing the boot pins in OTP. For more details, see the TMS320F2837xD Dual-Core Delfino Microcontrollers Technical Reference Manual.