PIC18F6520-I Datasheet, PDF (150/380 Pages) Micrel Semiconductor – 64/80-Pin High-Performance, 256 Kbit to 1 Mbit Enhanced Flash Microcontrollers with A/D

PIC18F6520/8520/6620/8620/6720/8720
15.2 Timer4 Interrupt
The Timer4 module has an 8-bit period register, PR4,
which is both readable and writable. Timer4 increments
from 00h until it matches PR4 and then resets to 00h on
the next increment cycle. The PR4 register is initialized
to FFh upon Reset.
FIGURE 15-1:
TIMER4 BLOCK DIAGRAM
15.3 Output of TMR4
The output of TMR4 (before the postscaler) is used
only as a PWM time base for the CCP modules. It is not
used as a baud rate clock for the MSSP, as is the
Timer2 output.
TMR4
Output⁽¹⁾
Sets Flag
bit TMR4IF
FOSC/4
Prescaler
1:1, 1:4, 1:16
2
T4CKPS1:T4CKPS0
TMR4
Reset
Comparator
Postscaler
EQ ^{1:1 to 1:16}
PR4
4
T4OUTPS3:T4OUTPS0
TABLE 15-1: REGISTERS ASSOCIATED WITH TIMER4 AS A TIMER/COUNTER
Name Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
all other
Resets
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE
RBIE TMR0IF INT0IF RBIF 0000 0000 0000 0000
IPR3
—
—
RC2IP
TX2IP TMR4IP CCP5IP CCP4IP CCP3IP --11 1111 --00 0000
PIR3
—
—
RC2IF
TX2IF TMR4IF CCP5IF CCP4IF CCP3IF --00 0000 --00 0000
PIE3
—
—
RC2IE
TX2IE TMR4IE CCP5IE CCP4IE CCP3IE --00 0000 --00 0000
TMR4 Timer4 Module Register
0000 0000 0000 0000
T4CON
— T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0 -000 0000 -000 0000
PR4 Timer4 Period Register
1111 1111 1111 1111
Legend: x = unknown, u = unchanged, – = unimplemented, read as ‘0’. Shaded cells are not used by the Timer4 module.
DS39609B-page 148
 2004 Microchip Technology Inc.