Note from item 12 that the ReNum bit is unchanged after a USB bus reset. Therefore, if a
device has ReNumerated and loaded a new personality, it retains the new personality
through a USB bus reset.
10.6 EZ-USB Disconnect
Table 10-3. Effects of an EZ-USB Disconnect and Re-connect
Default
Value
Item
Register
Endpt Data
Comment
1
2
3
4
5
6
7
8
9
uuuuuuuu u = unchanged
Byte Counts
CPUCS
uuuuuuuu
uuuuuuuu
PORT Configs
PORT Registers
PORT OEs
uuuuuuuu
uuuuuuuu
uuuuuuuu
Interrupt Enables
Interrupt Reqs
Bulk IN C/S
uuuuuuuu
uuuuuuuu
00000000 unarm, clear stall bit
10 Bulk OUT C/S
11 Toggle Bits
12 USBCS
00000000 Arm, clear stall bit
00000000 reset
uuuuuuuu ReNum bit unchanged
13 FNADDR
00000000 USB Function Address
14 IN07VAL
uuuuuuuu
uuuuuuuu
uuuuuuuu
uuuuuuuu
uuuuuuuu
0
15 OUT07VAL
16 INISOVAL
17 OUTISOVAL
18 USBPAIR
19 Configuration
20 Alternate Setting
0
Although not strictly a “reset,” when the EZ-USB simulates a disconnect-reconnect in
order to ReNumerate , there are effects on the EZ-USB core:
•
•
•
Bulk IN endpoints are unarmed, and bulk OUT endpoints are armed (9-10).
Endpoint STALL bits are cleared (9-10).
Data toggles are reset (11).
EZ-USB TRM v1.9
Chapter 10. EZ-USB Resets
Page 10-7
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