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CHAPTER 6 USB CONTROLLER
386
Preliminary User’s Manual S14767EJ1V0UM00
6.2.2.10
USB EP3 Control Register (U_EP3CR): 2CH
31
16
15
0
Reserved
30
Reserved
EP3EN
MAXP3
6
7
NAK3
SS3
17
R
18
19
TM3
20
Register for setting the operation of EndPoint3.
If the value in the MAXP field is rewritten during a send or receive operation, the operation of USB Controller may
become unpredictable. Therefore the MAXP can be written to once only, when initial setting is being performed.
Bit
Field
Description
R/W
31
EP3EN
(EndPoint Enable)
If the V
R
4120A RISC Processor sets this bit to 1, EndPoint3 is enabled for
transmitting and receiving data from and to USB.
R/W
30-20
Reserved
Reserved for future use
R
19
TM3
(Tx Mode)
Bit for setting the send mode.
When this bit is set to 0, sending is performed in SZLP Mode.
When this bit is set to 1, sending is performed in NZLP Mode.
For a detailed explanation of the send modes, see Section 6.5.3.
R/W
18
SS3
(Send Stall)
If the V
R
4120A RISC Processor sets this bit to 1, STALL packet is sent by
EndPoint3.
R/W
17
Reserved
Reserved for future use
R
16
NAK3
If the V
R
4120A RISC Processor sets this bit to 1, NAK packet is sent by
EndPoint3.
R/W
15-7
Reserved
Reserved for future use
R
6-0
MAXP3
(MAX Packet size)
Register that stores the Max Packet Size for EndPoint3. Prior to the start of
a USB transaction, the V
R
4120A RISC Processor must write an appropriate
value into this register.
When this field contains 0, no transaction is performed at EndPoint3.
R/W