DSP C6743 UART BOOT为什么在上电后用串口助手可以收到BOOTME，但在UART BOOT HOST里若勾选Wait for BOOTME却出现错误：(AIS Parse): Waiting for BOOTME... (power on or reset target now)

(File IO): Read 5940 bytes from file G:\DSP\MEMS3\flash_SPI\sdram\Debug\11.bin.
(Serial Port): Opening COM1 at 115200 baud...
(AIS Parse): Read magic word 0x41504954.
(AIS Parse): Waiting for BOOTME... (power on or reset target now)
(Serial Port): Read error! (The operation has timed out.)
(AIS Parse): Read invalid BOOTME string.
(AIS Parse): Boot aborted.
(Serial Port): Closing COM1.