无法使用M25P32 SPI闪存的启动VID PID

你好，
我试图建立的FX3S USB bootloader使用自定义VID和PID存储在微米M25P32 SPI Flash芯片。该板设置为SPI引导与USB回退。Flash图像工作的FX3 dvks板载闪存（M25P40）。图像被正确写入我的自定义板Flash（固件回读），但不能使用Flash Bootloader VID PID。用我观察引导读第一个身份登记的示波器（头）的Flash图像作为它的深度。在阅读标题和列举的默认柏VID PID在自定义板停止沟通。在自定义板FX3的SPI接口是使用1.8v水平和沟通，3.3V的闪光通过MAX3378双向电平转换器。我试图消除使用3.3V的水平对FX3的SPI的电平转换器和连接直接到3.3V的闪光（在三态电平移位器的远端），但仍然有同样的行为。
我想尝试不同类型的闪存，避免通过电平转换器。对于闪存类型有什么已知的问题吗？
图像标题设置为Bootloader使用10mhz SPI时钟（电平转换，马克斯的速度但Bootloader没有得到足够远，使用信息）。本应用笔记提醒使用拉上下/味噌&；MOSI（Bootloader预计浮线开始沟通）。电平移位器仍然是一个问题吗？我想引导甚至不会开始沟通如果电平转换器已拉上/下的行为。
提前感谢



     以下为原文
  Hi,
    I am trying to set up the FX3s USB bootloader to use custom VID and PID stored in a micron M25P32 SPI flash chip. The board is set to SPI boot with USB fallback. The flash image is working on the FX3 DVKs onboard flash (M25P40). The image is written correctly to the flash on my custom board (read back by firmware), but the bootloader fails to use the VID PID from flash. Using the oscilloscope I have observed the bootloader to read the status register and the first 4 bytes (header) of the flash image as it does on the DVK. The communication on the custom board stops after reading the header and it enumerates with default cypress VID PID. The FX3's SPI interface on the custom board is using 1.8V levels and communicating to the 3.3V flash through a MAX3378 bidirectional level shifter. I have tried eliminating the level shifter using 3.3V levels on the FX3's SPI and connecting it directly to the 3.3V flash(on the far end of the tristated level shifter), but still got the same behaviour.
    I intend to try different types of flash memory and avoid going through the level shifter. Are there any known issues for certain flash types?
    The image header is set to for the bootloader to use 10MHz SPI clock(Max speed of level shifter, but the bootloader doesn't get far enough to use that information). The app note warns of using pull up/down on MISO & MOSI(bootloader expects floating lines to start communication). Could the level shifter still be a problem? I would guess the bootloader would not even start communicating if the level shifter has pull up/down behaviour.
    Thanks in advance