Using the I2C ROM bootloader:
In the document, TM4C-BOOTLDR-UG-2.2.0.295.pdf, the description under COMMAND_DOWNLOAD recommends that this command be followed by a COMMAND_GET_STATUS.
Under the command, COMMAND_SEND_DATA, it says that this command can only follow COMMAND_DOWNLOAD, or another COMMAND_SEND_DATA.
If the COMMAND_DOWNLOAD is followed by COMMAND_GET_STATUS, the first COMMAND_SEND_DATA locks up with the SCL line pulled low.
If the COMAND_DOWNLOAD is followed by COMMAND_SEND_DATA, the whole process completes successfully
