例16_CH554 模擬HID兼容和鍵盤復(fù)合設(shè)備實(shí)例

中的設(shè)備描述符為

0x12,0x01,

0x10,0x01,

0x00,0x00,

0x00,0x08,? ? ? ? ? ? ? ? ? ? ??

0x31,0x51,// Vendor ID? ?|? VID =? 0X5131///413c

0x07,0x20,// Product ID? |? PID = 0X2007 /// 2105

0x00,0x11,// bcdDevic

0x00,0x00,

0x00,0x01

我修改為

????????0x12 0x01?

????????0x00 0x02?

????????0x00 0x00

????????0x00 0x40

????????0xF2 0x0C?

????????0x01 0xA1?

????????0x00 0x01?

????????0x01 0x02?

????????0x03 0x01

電腦顯示無法識別，然后我有邏輯分析儀觀察，發(fā)現(xiàn)在主機(jī)分配新地址之后，芯片使用新地址上傳設(shè)備描述符的時候，只上傳前面8個字節(jié)（0X12~0X40），還有10個字節(jié)不會上傳，

這是怎么回事？

you specify a bMaxPacketSize0 of 0x40.?

Therefore you have to copy the 0x12 bytes at once. If a descriptor is bigger than?bMaxPacketSize0 the transfer needs to be devided in chunks of sizeof(bMaxPacketSize0).

Of course the EP0 Dma buffers have to be big enough too.