请问为什么C6743 UART BOOT在AISgen没有使能CRC、UART BOOT HOST 里没有勾选Wait for BOOTME情况下，有时好使，有时不好使，不好使时出现如下错误：

补充：在使能CRC、UART BOOT HOST 里勾选Wait for BOOTME情况下一直不好使

(File IO): Read 5900 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): Performing Start-Word Sync...
(Serial Port): Read error! (The operation has timed out.)
(AIS Parse): I/O Error in read!
(AIS Parse): Boot aborted.
(Serial Port): Closing COM1.