USB Host Lite on the LPC1788

Yes - definitely needed to relocate to 0x2000 0000 - actually, 0x20002000 and 0x20004000 work fine as well. One thing for sure, you'll never get this example to work if you don't initialize the FAT_BootSec structure used in usbhost_fat.c

adding this simple line will make your life less stressful:

I put it right after the file entry initialization.

The reason for this is the structure element BootSecOffset. If your boot record contains what you need, and you don't have an LBA to jump to, this element will never get initialized, and it's value can be anything, which will throw off all your sector calculations...

Other than that, it's a pretty basic demo of using the HC to talk to a USB memory stick...

Hope this helps,

Hello Dave,

I read your post on http://tech.groups.yahoo.com/group/lpc2000/message/54764 and it looks like you have received confirmation on the proper base address.

The basic issue here is that the example source you were using was for the LPC176x and LPC175x line of parts. The parts that you are using have a different die and so the base addresses are different.

As you learned on the other forum, the proper base address for the LPC177x/8x is 0x20004000.

The code that you downloaded from nxp.com is a bit old and will be updated soon but it will still not support the LPC177x/8x parts. In the near future a new zip file will be posted on the same page that will support those parts.

Why is 0x20004000 preferred over say 0x20000000 or 0x20002000? Isn't this peripheral RAM available to all peripherals? Or is there something special about 0x20004000 that better suits the HC?

Thanks for your help in advance,