TM4C123GH6ZRB Datasheet, PDF (379/1471 Pages) Texas Instruments – Tiva Microcontroller

Tiva^™ TM4C123GH6ZRB Microcontroller
Register 82: Universal Serial Bus Sleep Mode Clock Gating Control
(SCGCUSB), offset 0x728
The SCGCUSB register provides software the capability to enable and disable the USB module in
sleep mode. When enabled, a module is provided a clock. When disabled, the clock is disabled to
save power. This register provides the same capability as the legacy Sleep Mode Clock Gating
Control Register n SCGCn registers specifically for the watchdog modules and has the same bit
polarity as the corresponding SCGCn bits.
Important: This register should be used to control the clocking for the USB module. To support
legacy software, the SCGC2 register is available. A write to the USB0 bit in the SCGC2
register also writes the S0 bit in this register. If the USB0 bit is changed by writing to the
SCGC2 register, it can be read back correctly with a read of the SCGC2 register. If
software uses this register to control the clock for the USB module, the write causes
proper operation, but the USB0 bit in the SCGC2 register does not reflect the value of
the S0 bit. If software uses both legacy and peripheral-specific register accesses, the
peripheral-specific registers must be accessed by read-modify-write operations that
affect only peripherals that are not present in the legacy registers. In this manner, both
the peripheral-specific and legacy registers have coherent information.
Universal Serial Bus Sleep Mode Clock Gating Control (SCGCUSB)
Base 0x400F.E000
Offset 0x728
Type RW, reset 0x0000.0000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
reserved
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
reserved
S0
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RW
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit/Field
31:1
0
Name
reserved
S0
Type
RO
RW
Reset
0
0
Description
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
USB Module Sleep Mode Clock Gating Control
Value Description
0 USB module is disabled.
1 Enable and provide a clock to the USB module in sleep mode.
June 12, 2014
379
Texas Instruments-Production Data