PIC18F23K22 Datasheet, PDF (56/492 Pages) Microchip Technology – 28/40/44-Pin, Low-Power, High-Performance Microcontrollers with nanoWatt XLP Technology

PIC18(L)F2X/4XK22
3.6 Selective Peripheral Module
Control
Idle mode allows users to substantially reduce power
consumption by stopping the CPU clock. Even so,
peripheral modules still remain clocked, and thus, con-
sume power. There may be cases where the applica-
tion needs what IDLE mode does not provide: the
allocation of power resources to the CPU processing
with minimal power consumption from the peripherals.
PIC18(L)F2X/4XK22 family devices address this
requirement by allowing peripheral modules to be
selectively disabled, reducing or eliminating their
power consumption. This can be done with control bits
in the Peripheral Module Disable (PMD) registers.
These bits generically named XXXMD are located in
control registers PMD0, PMD1 or PMD2.
Setting the PMD bit for a module disables all clock
sources to that module, reducing its power
consumption to an absolute minimum. In this state, the
control and STATUS registers associated with the
peripheral are also disabled, so writes to these
registers have no effect and read values are invalid.
REGISTER 3-1: PMD0: PERIPHERAL MODULE DISABLE REGISTER 0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
UART2MD UART1MD TMR6MD TMR5MD TMR4MD TMR3MD TMR2MD TMR1MD
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
UART2MD: UART2 Peripheral Module Disable Control bit
1 = Module is disabled, Clock Source is disconnected, module does not draw digital power
0 = Module is enabled, Clock Source is connected, module draws digital power
bit 6
UART1MD: UART1 Peripheral Module Disable Control bit
1 = Module is disabled, Clock Source is disconnected, module does not draw digital power
0 = Module is enabled, Clock Source is connected, module draws digital power
bit 5
TMR6MD: Timer6 Peripheral Module Disable Control bit
1 = Module is disabled, Clock Source is disconnected, module does not draw digital power
0 = Module is enabled, Clock Source is connected, module draws digital power
bit 4
TMR5MD: Timer5 Peripheral Module Disable Control bit
1 = Module is disabled, Clock Source is disconnected, module does not draw digital power
0 = Module is enabled, Clock Source is connected, module draws digital power
bit 3
TMR4MD: Timer4 Peripheral Module Disable Control bit
1 = Module is disabled, Clock Source is disconnected, module does not draw digital power
0 = Module is enabled, Clock Source is connected, module draws digital power
bit 2
TMR3MD: Timer3 Peripheral Module Disable Control bit
1 = Module is disabled, Clock Source is disconnected, module does not draw digital power
0 = Module is enabled, Clock Source is connected, module draws digital power
bit 1
TMR2MD: Timer2 Peripheral Module Disable Control bit
1 = Module is disabled, Clock Source is disconnected, module does not draw digital power
0 = Module is enabled, Clock Source is connected, module draws digital power
bit 0
TMR1MD: Timer1 Peripheral Module Disable Control bit
1 = Module is disabled, Clock Source is disconnected, module does not draw digital power
0 = Module is enabled, Clock Source is connected, module draws digital power
DS41412B-page 56
Preliminary
 2010 Microchip Technology Inc.