28 USB FUNCTION CONTROLLER (USB)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
28-35
USB_Control (USB Control)
Register name Address
Bit
Name
Setting
Init. R/W
Remarks
USB_Control
(USB control)
0x300c21
(8 bits)
D7
DisBusDetect
1 Disable bus detect
0 Enable bus detect
0
R/W
D6
EnAutoNego
1 Enable auto negotiation
0 Disable auto negotiation
0
R/W
D5
InSUSPEND
1 Monitor NonJ
0 Do nothing
0
R/W
D4
StartDetectJ
1 Start J-state detection
0 Do nothing
0
R/W
D3
SendWakeup
1 Send remote wakeup signal 0 Do nothing
0
R/W
D2–1 –
–
–
–
0 when being read.
D0
ActiveUSB
1 Activate USB
0 Deactivate USB
0
R/W
The operation setting is done for the USB.
D7
DisBusDetect
Setting this bit to 1 disables the automatic detection of the USB reset/suspend state.
When this bit is set to 0 (to be cleared), activities on the USB bus is monitored to detect the reset/sus-
pend state.
If the bus activities cannot be detected within 3 ms, the USB is determined to be suspend state. And
if “SE0” longer than 2.5 µs is detected, the USB is determined to be reset state, and then the relevant
cause of interrupt (DetectReset, DetectSuspend) is set.
If the DetectReset or the DetectSuspend bit is set to 1, set the DisBusDetect bit to 1 to disable detection
when the reset/suspend state is continued.
When using the Auto Negotiation function, do not set this bit to 1.
D6
EnAutoNego
This bit enables the Auto Negotiation function. The Auto Negotiation function automates the work se-
quence to be done after detecting the reset, from the end of the speed negotiation to determination of
the speed mode. Refer to the section describing operations for details of the Auto Negotiation.
D5
InSUSPEND
This bit enables the detection of the NonJ state. If the USB suspend state is detected and f/w is pre-
pared. set this bit to 1. To return from the suspended state, set this bit to 0 (to be cleared).
The NonJ state can be detected only when this bit is set. If the Snooze function is not be used when the
USB goes into the suspend state, set this bit.
Refer to description on operations for how to use the Auto Negotiation function.
D4
StartDetectJ
This bit enables the detection of the J state. After setting this bit and J-state is coming, DetectJ interrupt
is set when EnDetectJ is set.
D3
SendWakeup
Setting this bit to 1 outputs the RemoteWakeup signal (K) to the USB port.
Within the time between 1 ms and 15 ms after starting to send the RemoteWakeup signal, set this bit to
0 (to be cleared) to stop sending the signals.
D[2:1]
Reserved
D0
ActiveUSB
Since this bit is set to 0 (to be cleared) after hardware reset, all USB functions are stopped. The opera-
tion as a USB will be enabled by setting this bit to 1 after completing the setting of this IC.
USB_Status (USB Status)
Register name Address
Bit
Name
Setting
Init. R/W
Remarks
USB_Status
(USB status)
0x300c22
(8 bits)
D7
VBUS
1 VBUS=High
0 VBUS=Low
X
R
D6
FS
1 FS mode (fixed)
0 –
1
R
D5–2 –
–
–
–
0 when being read.
D1–0 LineState[1:0]
LineState[1:0]
DP/DM
X
R
0x3
0x2
0x1
0x0
SE1
K
J
SE0
This register displays the status related to the USB.
This register is valid during snooze as well.