Microchip Technology DM183037 Data Sheet
2012 Microchip Technology Inc.
DS30575A-page 295
PIC18F97J94 FAMILY
16.2
Timer2/4/6/8 Interrupt
The Timer2/4/6/8 modules have eight-bit Period
registers, PRx, that are both readable and writable.
Timer2/4/6/8 increment from 00h until they match PR2/
4/6/8 and then reset to 00h on the next increment cycle.
The PRx registers are initialized to FFh upon Reset.
registers, PRx, that are both readable and writable.
Timer2/4/6/8 increment from 00h until they match PR2/
4/6/8 and then reset to 00h on the next increment cycle.
The PRx registers are initialized to FFh upon Reset.
16.3
Output of TMRx
The outputs of TMRx (before the postscaler) are used
only as a PWM time base for the ECCP modules. They
are not used as baud rate clocks for the MSSPx
modules as is the Timer2 output.
only as a PWM time base for the ECCP modules. They
are not used as baud rate clocks for the MSSPx
modules as is the Timer2 output.
FIGURE 16-1:
TIMER2/4/6/8 BLOCK DIAGRAM
REGISTER 16-1:
TxCON: TIMERx CONTROL REGISTER (TIMER2/4/6/8)
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
TxOUTPS3
TxOUTPS2
TxOUTPS1
TxOUTPS0
TMRxON
TxCKPS1
TxCKPS0
bit 7
bit 0
Legend:
R = Readable bit
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
Unimplemented: Read as ‘0’
bit 6-3
TxOUTPS<3:0>: Timerx Output Postscale Select bits
0000 = 1:1 Postscale
0001 = 1:2 Postscale
•
•
•
1111 = 1:16 Postscale
0000 = 1:1 Postscale
0001 = 1:2 Postscale
•
•
•
1111 = 1:16 Postscale
bit 2
TMRxON: Timerx On bit
1 = Timerx is on
0 = Timerx is off
1 = Timerx is on
0 = Timerx is off
bit 1-0
TxCKPS<1:0>: Timerx Clock Prescale Select bits
00 = Prescaler is 1
01 = Prescaler is 4
1x = Prescaler is 16
00 = Prescaler is 1
01 = Prescaler is 4
1x = Prescaler is 16
Comparator
TMRx Output
TMRx
Postscaler
Prescaler
PRx
2
F
OSC
/4
1:1 to 1:16
1:1, 1:4, 1:16
4
TxOUTPS<3:0>
TxCKPS<1:0>
Set TMRxIF
Internal Data Bus
8
Reset
TMRx/PRx
8
8
(to PWM)
Match