TM4C1292NCZAD Datasheet, PDF (484/1844 Pages) Texas Instruments – Tiva Microcontroller

System Control
Register 154: Quadrature Encoder Interface Power Control (PCQEI), offset
0x944
Important: The QEI 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 PCQEI register controls the power applied to the QEI 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 RCGCQEI, SCGCQEI and DCGCQEI registers. If the Rn, Sn, or Dn bit of the respective
RCGCQEI, SCGCQEI and DCGCQEI 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 PCQEI register
is.
However, if the Rn, Sn, or Dn bit of the respective RCGCQEI, SCGCQEI and DCGCQEI 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 PCQEI 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 5-30. Module Power Control
Rn, Sn or Dn Value in
Respective RCGCx,
SCGCx, or DCGCx
Register
0
0
1
Pn Description
0 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.
1 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.
X Module is powered and receives a clock.
Quadrature Encoder Interface Power Control (PCQEI)
Base 0x400F.E000
Offset 0x944
Type RW, reset 0x0000.0001
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
P0
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
1
484
June 18, 2014
Texas Instruments-Production Data