23 usb control register (usb_ctrl) – Freescale Semiconductor ColdFire MCF52210 User Manual
Page 259
Universal Serial Bus, OTG Capable Controller
MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor
15-31
15.4.1.23 USB Control Register (USB_CTRL)
IPSBAR
Offset:
0x1C_0100 (USB_CTRL)
Access: User read/write
7
6
5
4
3
2
1
0
R
SUSP
PDE
—
—
—
—
CLK_SRC
W
Reset:
0
1
0
0
0
0
1
1
Figure 15-30. USB Control Register
Table 15-35. USB_CTRL Field Descriptions
Field
Description
7
SUSP
Places the USB transceiver into the suspend state.
0
USB transceiver is not in suspend state.
1
USB transceiver is in suspend state.
6
PDE
Enables the non-functional weak pulldowns on the USB transceiver
0 Weak pulldowns are disabled on D+ and D–
1 Weak pulldowns are enabled on D+ and D–
5 –2
Reserved
1 – 0
CLK_SRC
Determines the clock source for the USB 48 MHZ clock
00
USB_ALT_CLK pin
01
Oscillator clock
10
Reserved
11
System clock source