Device Initialization
13-81
USB Function Module
Figure 13–10. Device Configuration Routine
End of Device
Configuration
Routine
Enter Device
Configuration
Routine
Endpoint Configuration
Configured
endpoint values must
match values returned
in descriptors during
the enumeration
phase.
Set
SYSCON1.Cfg_Lock
to 1
Fill other SYSCON1
fields (Nak_En,
Self_Pwr, SOFF_Dis,
Pullup_En)
The LH can keep
Pullup_En value set to
0 if not ready to
communicate with the
USB host.
No
At this point, the LH must initialize all flags used
by ISR flowcharts, including:
– Set DS_mem flag to 0x0000 (see device
state changed handler).
– Set control read and control write flags to 0.
– Set FIFO not full and double-buffer flag to 0.
Fill IRQ_EN register with
appropriate value to enable
needed interrupt signals
After a USB reset, all IRQ_EN
registers except DS_Chg are
cleared. They must be re-
enabled.