18F8680 datasheet(161/496 Pages) MICROCHIP

161 / 496 page

 2004 Microchip Technology Inc.

DS30491C-page 159

PIC18F6585/8585/6680/8680

12.0

TIMER1 MODULE

The Timer1 module timer/counter has the following

features:

• 16-bit timer/counter

(two 8-bit registers; TMR1H and TMR1L)

• Readable and writable (both registers)

• Internal or external clock select

• Interrupt on overflow from 0FFFFh to 0000h

• Reset from CCP module special event trigger

Figure 12-1 is a simplified block diagram of the Timer1

module.

module and contains the Timer1 Oscillator Enable bit

(T1OSCEN). Timer1 can be enabled or disabled by

setting or clearing control bit, TMR1ON (T1CON<0>).

T1CON: TIMER1 CONTROL REGISTER

R/W-0

U-0

R/W-0

RD16

—

T1CKPS1

T1CKPS0

T1OSCEN

T1SYNC

TMR1CS

TMR1ON

bit 7

bit 0

bit 7

RD16: 16-bit Read/Write Mode Enable bit

= Enables register read/write of Timer1 in one 16-bit operation

= Enables register read/write of Timer1 in two 8-bit operations

bit 6

Unimplemented: Read as ‘0’

bit 5-4

T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits

= 1:8 prescale value

= 1:4 prescale value

= 1:2 prescale value

= 1:1 prescale value

bit 3

T1OSCEN: Timer1 Oscillator Enable bit

= Timer1 oscillator is enabled

= Timer1 oscillator is shut-off

The oscillator inverter and feedback resistor are turned off to eliminate power drain.

bit 2

T1SYNC: Timer1 External Clock Input Synchronization Select bit

When TMR1CS = 1:

= Do not synchronize external clock input

= Synchronize external clock input

When TMR1CS = 0:

This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.

bit 1

TMR1CS: Timer1 Clock Source Select bit

= External clock from pin RC0/T1OSO/T13CKI (on the rising edge)

= Internal clock (FOSC/4)

bit 0

TMR1ON: Timer1 On bit

= Enables Timer1

= Stops Timer1

Legend:

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

18F8680 Datasheet(PDF) 161 Page - Microchip Technology

18F8680 Datasheet(HTML) 161 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL