4.2.154 PCUART Register (Offset = 0x918) [reset = 0xFF]
Universal Asynchronous Receiver/Transmitter Power Control (PCUART)
NOTE
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 regardless 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. Table 4-173 details the differences.
Table 4-173 Module Power Control
| Rn, Sn, or Dn Value in Respective RCGCx, SCGCx, or DCGCx Register |
Pn |
Description |
| 0 |
0 |
Module is not powered and does not receive a clock. In this case, the state of the peripheral is not retained.
This is the lowest power consumption state of any peripheral, because 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 1 or the P0 bit is changed to 1.
Software must reinitialize the peripheral when reenabled due to the loss of state.
|
| 0 |
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, because it consumes only leakage current.
|
| 1 |
X |
Module is powered and receives a clock. |
PCUART is shown in Figure 4-160 and described in Table 4-174.
Return to Summary Table.
Figure 4-160 PCUART Register
| 31 |
30 |
29 |
28 |
27 |
26 |
25 |
24 |
23 |
22 |
21 |
20 |
19 |
18 |
17 |
16 |
| RESERVED |
| R-0x0 |
|
| 15 |
14 |
13 |
12 |
11 |
10 |
9 |
8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| RESERVED |
P7 |
P6 |
P5 |
P4 |
P3 |
P2 |
P1 |
P0 |
| R-0x0 |
R/W-0x1 |
R/W-0x1 |
R/W-0x1 |
R/W-0x1 |
R/W-0x1 |
R/W-0x1 |
R/W-0x1 |
R/W-0x1 |
|
Table 4-174 PCUART Register Field Descriptions
| Bit |
Field |
Type |
Reset |
Description |
| 31-8 |
RESERVED |
R |
0x0 |
|
| 7 |
P7 |
R/W |
0x1 |
UART Module 7 Power Control. The Pn bit encodings do not apply if the corresponding bit in the RCGCUART, SCGCUART, or DCGCUART register is clear.
0x0 = The UART module 7 is not powered and does not receive a clock. In this case, the state of the module is not retained. This configuration provides the lowest power consumption state.
0x1 = The UART module 7 is powered but does not receive a clock. In this case, the module is inactive.
|
| 6 |
P6 |
R/W |
0x1 |
UART Module 6 Power Control. The Pn bit encodings do not apply if the corresponding bit in the RCGCUART, SCGCUART, or DCGCUART register is clear.
0x0 = The UART module 6 is not powered and does not receive a clock. In this case, the state of the module is not retained. This configuration provides the lowest power consumption state.
0x1 = The UART module 6 is powered but does not receive a clock. In this case, the module is inactive.
|
| 5 |
P5 |
R/W |
0x1 |
UART Module 5 Power Control. The Pn bit encodings do not apply if the corresponding bit in the RCGCUART, SCGCUART, or DCGCUART register is clear.
0x0 = The UART module 5 is not powered and does not receive a clock. In this case, the state of the module is not retained. This configuration provides the lowest power consumption state.
0x1 = The UART module 5 is powered but does not receive a clock. In this case, the module is inactive.
|
| 4 |
P4 |
R/W |
0x1 |
UART Module 4 Power Control. The Pn bit encodings do not apply if the corresponding bit in the RCGCUART, SCGCUART, or DCGCUART register is clear.
0x0 = The UART module 4 is not powered and does not receive a clock. In this case, the state of the module is not retained. This configuration provides the lowest power consumption state.
0x1 = The UART module 4 is powered but does not receive a clock. In this case, the module is inactive.
|
| 3 |
P3 |
R/W |
0x1 |
UART Module 3 Power Control. The Pn bit encodings do not apply if the corresponding bit in the RCGCUART, SCGCUART, or DCGCUART register is clear.
0x0 = The UART module 3 is not powered and does not receive a clock. In this case, the state of the module is not retained. This configuration provides the lowest power consumption state.
0x1 = The UART module 3 is powered but does not receive a clock. In this case, the module is inactive.
|
| 2 |
P2 |
R/W |
0x1 |
UART Module 2 Power Control. The Pn bit encodings do not apply if the corresponding bit in the RCGCUART, SCGCUART, or DCGCUART register is clear.
0x0 = The UART module 2 is not powered and does not receive a clock. In this case, the state of the module is not retained. This configuration provides the lowest power consumption state.
0x1 = The UART module 2 is powered but does not receive a clock. In this case, the module is inactive.
|
| 1 |
P1 |
R/W |
0x1 |
UART Module 1 Power Control. The Pn bit encodings do not apply if the corresponding bit in the RCGCUART, SCGCUART, or DCGCUART register is clear.
0x0 = The UART module 1 is not powered and does not receive a clock. In this case, the state of the module is not retained. This configuration provides the lowest power consumption state.
0x1 = The UART module 1 is powered but does not receive a clock. In this case, the module is inactive.
|
| 0 |
P0 |
R/W |
0x1 |
UART Module 0 Power Control. The Pn bit encodings do not apply if the corresponding bit in the RCGCUART, SCGCUART, or DCGCUART register is clear.
0x0 = The UART module 0 is not powered and does not receive a clock. In this case, the state of the module is not retained. This configuration provides the lowest power consumption state.
0x1 = The UART module 0 is powered but does not receive a clock. In this case, the module is inactive.
|