NEC switch User Manual
Page 120
CHAPTER 8 USB FUNCTION
User’s Manual U12978EJ3V0UD
120
(8) USB timer start reservation control register (USBTCL)
This register reserves USB timer start after reception of a SETUP/OUT packet or transmission of a data packet.
USBTCL is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets USBTCL to 01H.
SETUP reception
Note
also sets USBTCL to 01H.
Note SETUP reception implies the satisfaction of all the following three conditions.
• Matching of address
• Endpoint 0 received
• No error in reception
Figure 8-18. Format of USB Timer Start Reservation Control Register
Symbol
6
7
5
4
3
2
1
0
0
0
0
0
0
0
DATATX SETORX
DATATX
USB timer start reservation after data packet transmission
0
1
FF6CH
Address
USBTCL
After reset
01H
R/W
R/W
Do not start USB timer.
USB timer starts when all the following conditions are satisfied in EOP during data packet transmission.
DIDRST = 1, DBYER = 0, DBITER = 0, CR16ER = 0
SETORX
USB timer start reservation after SETUP/OUT token packet reception
0
1
Do not start USB timer.
USB timer starts when all the following conditions are satisfied in EOP during SETUP/OUT token packet reception.
OUTRX (internal signal) = 1 or SETRX = 1, ADRRST = 1, END0RX = 1, TBYER = 0, TBITER = 0, CRC5ER = 0