Register 150: Universal Asynchronous Receiver/Transmitter Power Control
(PCUART), offset 0x918
Important:
The UART module does not currently provide the ability to respond to the power down
request. Setting a bit in this register has no effect on power consumption. This register
is defined for future software compatibility.
The
PCUART
register controls the power applied to the UART module. The function of this bit
depends on the current state of the device (Run, Sleep or Deep-Sleep mode) and value of the
corresponding bits in the
RCGCUART
,
SCGCUART
and
DCGCUART
registers. If the
Rn
,
Sn
, or
Dn
bit of the respective
RCGCUART
,
SCGCUART
and
DCGCUART
registers is 1 and the device
is in that mode, the module is powered and receives a clock irrespective of what the corresponding
Pn
bit in the
PCUART
register is.
However, if the
Rn
,
Sn
, or
Dn
bit of the respective
RCGCUART
,
SCGCUART
and
DCGCUART
registers is 0 and the device is in that mode, then the module behaves differently depending on the
value of the corresponding
Pn
bit in the
PCUART
register. In this case, when the
Pn
bit is clear the
module is not powered and does not receive a clock. If the
Pn
bit is set, the module is powered but
does not receive a clock. The table below details the differences.
Table 5-22. Module Power Control
Description
Pn
Rn, Sn or Dn Value in
Respective RCGCx,
SCGCx, or DCGCx
Register
Module is not powered and does not receive a clock. In this case, the peripheral's
state is not retained.
This is the lowest power consumption state of any peripheral since it consumes no
dynamic nor leakage current. Hardware should perform a peripheral reset if the active
mode changes and the
RCGCx
,
SCGCx
, or
DCGCx
register is a 1 or the
P0
bit is
changed to a 1.
Software must re-initialize the peripheral when re-enabled due to the loss of state.
0
0
Module is powered, but does not receive a clock.
In this case, the peripheral is inactive. This is the second-lowest power consumption
of any peripheral since it consumes only leakage current.
1
0
Module is powered and receives a clock.
X
1
Universal Asynchronous Receiver/Transmitter Power Control (PCUART)
Base 0x400F.E000
Offset 0x918
Type RW, reset 0x0000.00FF
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
reserved
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Type
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Reset
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
P0
P1
P2
P3
P4
P5
P6
P7
reserved
RW
RW
RW
RW
RW
RW
RW
RW
RO
RO
RO
RO
RO
RO
RO
RO
Type
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
Reset
467
June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller