Usb Attach/Detach Register - Renesas M16C Series User Manual

M30240 Group
USB Control Register
b7 b6 b5 b4 b3
O O O
Figure 3.7: USB Control Register (USBC)

3.2.2.2 USB Attach/Detach Register

The USB Attach/Detach Register is used to attach and detach the device from the USB host in the
USB communication standards without the physical attachment/detachment of the USB cable.
• Port 8 -Second Bit
3
When this bit is "0", Port 8
When this bit is "1", Port P8
the D+ line. When the stealth detach function is used, a 1.5kΩ resistor must be connected between
P8 and the D+ pin. When the stealth detach function is not used, the 1.5kΩ resistor should be placed
3
between EXTCAP and D+.
• Attach/Detach Selection Bit
When this bit is "0", the USB host will detect a detach.
When this bit is "1", the USB host will detect an attach.
Figure 3.8 shows the structure of the Attach/Detach Register.
U S B A ttach/D eta ch R eg iste r
b7 b6 b5 b4 b3
O O O O O O
Figure 3.8: USB Attach/Detach Register (USBAD)
Rev.1.00 Sep 24, 2003 Page 296 of 360
b2 b1 b0
Symbol
USBC
Bit Symbol
Reserved
Tranceiver voltage converter
USBC3
High/Low current mode selection
USB Tranceiver voltage converter
USBC4
enable bit
USB clock enable bit
USBC5
USBC6 USB SOF port select bit
USBC7
USB enable bit
Note 1: For USB normal operation
Note 2: For USB suspend operation
Note 3: P8 is used as GPIO pin
6
Note 4: All USB internal registers are held at their default values.
operates as a normal CMOS port.
3
has a stealth detach function and becomes the 3.3V supply terminal for
3
b2 b1 b0
S ym bol
U S B A D
B it S ym bol
P 8 _2nd P ort 8
3
A ttach/D etach
A ttach/D etach
R eserved
Address
000C
16
Bit Name
Must always be set to "0"
0: High current mode (Note 1)
1: Low current mode (Note 2)
0: Disabled
1: Enabled
0: Disabled
1: Enabled
0: Disabled (Note 3)
1: Enabled
0: Disabled (Note 4)
1: Enabled
A ddress
001F
16
B it N am e
0 : N orm al m ode for P ort 8
-S econd
1 : F orces P ort 8
3
3
0 : T ri-states. P 8
3
detect a D etach
1 : D rives P 8 w ith voltage on E X T C A P ,
3
causing the host to detect an A ttach
M ust alw ays be set to "0"
Universal Serial Bus
When reset
00
16
Function R W
O O
O O
O O
O O
O O
O O
W hen reset
00
16
Function R W
3 O O
to perate as pull for D +
causing the host to
O O
O O