EZ-USB Datasheet, PDF (186/334 Pages) Cypress Semiconductor – The EZ-USB USB Integrated Circuit

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
Item
Register
1 Endpt Data
2 Byte Counts
3 CPUCS
4 PORT Configs
5 PORT Registers
6 PORT OEs
7 Interrupt Enables
8 Interrupt Reqs
9 Bulk IN C/S
10 Bulk OUT C/S
11 Toggle Bits
12 USBCS
13 FNADDR
14 IN07VAL
15 OUT07VAL
16 INISOVAL
17 OUTISOVAL
18 USBPAIR
19 Configuration
20 Alternate Setting
Default
Value
Comment
uuuuuuuu u = unchanged
uuuuuuuu
uuuuuuuu
uuuuuuuu
uuuuuuuu
uuuuuuuu
uuuuuuuu
uuuuuuuu
00000000 unarm, clear stall bit
00000000 Arm, clear stall bit
00000000 reset
uuuuuuuu ReNum bit unchanged
00000000 USB Function Address
uuuuuuuu
uuuuuuuu
uuuuuuuu
uuuuuuuu
uuuuuuuu
0
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