USB SIE command timing?

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by gbm on Thu Dec 09 08:03:00 MST 2010
LPC17xx use some cryptic stuff called SIE for USB interface. From the manuals it is not obvious how this secret hardware works. Some important actions of the USB interface are implemented as SIE commands. After the command is written, the SIE executes it and sets the CCEMPTY bit when ready.
My question is: how long does it take for SIE to execute a command? Is there any guaranteed maximum execution time? Is it reasonable to wait in a polling loop for the command to be executed inside an interrupt service routine, like the LPCUSB firmware does?

Either the documents are silent on this or I am too dumb to find the information in the manual and datasheet. NXPers, please help.