ZHCSH09 October 2017 MSP432E401Y
PRODUCTION DATA.
After POR and device initialization occurs, the hardware loads the stack pointer from either flash or ROM, based on the presence of an application in flash and the state of the EN bit in the BOOTCFG register.
If the flash address 0x0000.0004 contains an erased word (value 0xFFFF.FFFF) or the EN bit is of the BOOTCFG register is clear, the stack pointer and reset vector pointer are loaded from ROM at address 0x0100.0000 and 0x0100.0004, respectively. The bootloader executes and configures the available boot slave interfaces and waits for a programmer, host PC, or boot server to load its software. The bootloader uses a simple packet interface to provide synchronous communication with the device for I2C, SSI, and UART. The speed of the bootloader is determined by the frequency of the internal oscillator (PIOSC) or external crystal (if connected).
The ROM invokes the USB and Ethernet bootloader only when an external crystal is detected. Also, the Ethernet bootloader works only when a 25-MHz crystal is detected.
The following serial interfaces can be used:
If the check of the flash at address 0x0000.0004 contains a valid reset vector value and the EN bit in the BOOTCFG register is set, the stack pointer and reset vector values are fetched from the beginning of flash. This application stack pointer and reset vector are loaded and the processor executes the application directly. Otherwise, the stack pointer and reset vector values are fetched from the beginning of ROM.