AC162078 Microchip Technology, AC162078 Datasheet - Page 111

• Manufacturer Part Number: AC162078
• Description: HEADER INTRFC MPLAB ICD2 18F1330
• Manufacturer: Microchip Technology

Specifications of AC162078

• Accessory Type: Transition Header
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: ICD2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Not applicable / Not applicable

13.0
The Timer1 timer/counter module has the following
features:
• 16-bit timer/counter
• Readable and writable (both registers)
• Internal or external clock select
• Interrupt on overflow from FFFFh to 0000h
• Status of system clock operation
Figure 13-1 is a simplified block diagram of the Timer1
module.
REGISTER 13-1:
 2009 Microchip Technology Inc.
Note 1: Placement of T1OSI and T1OSO/T1CKI depends on the value of the Configuration bit, T1OSCMX, of CONFIG3H.
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6
bit 5-4
bit 3
bit 2
bit 1
bit 0
(two 8-bit registers; TMR1H and TMR1L)
R/W-0
RD16
TIMER1 MODULE
RD16: 16-Bit Read/Write Mode Enable bit
1 = Enables register read/write of Timer1 in one 16-bit operation
0 = Enables register read/write of Timer1 in two 8-bit operations
T1RUN: Timer1 System Clock Status bit
1 = Device clock is derived from Timer1 oscillator
0 = Device clock is derived from another source
T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits
11 = 1:8 Prescale value
10 = 1:4 Prescale value
01 = 1:2 Prescale value
00 = 1:1 Prescale value
T1OSCEN: Timer1 Oscillator Enable bit
1 = Timer1 oscillator is enabled
0 = Timer1 oscillator is shut off
The oscillator inverter and feedback resistor are turned off to eliminate power drain.
T1SYNC: Timer1 External Clock Input Synchronization Select bit
When TMR1CS = 1:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
When TMR1CS = 0:
This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.
TMR1CS: Timer1 Clock Source Select bit
1 = External clock from T1OSO/T1CKI (on the rising edge)
0 = Internal clock (F
TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1
T1RUN
R-0
T1CON: TIMER1 CONTROL REGISTER
W = Writable bit
‘1’ = Bit is set
T1CKPS1
R/W-0
OSC
/4)
T1CKPS0
R/W-0
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
T1OSCEN
R/W-0
Register 13-1 details the Timer1 Control register. This
register controls the operating mode of the Timer1
module and contains the Timer1 Oscillator Enable bit
(T1OSCEN). Timer1 can be enabled or disabled by
setting or clearing control bit, TMR1ON (T1CON<0>).
The Timer1 oscillator can be used as a secondary clock
source in power-managed modes. When the T1RUN bit
is set, the Timer1 oscillator provides the system clock. If
the Fail-Safe Clock Monitor is enabled and the Timer1
oscillator fails while providing the system clock, polling
the T1RUN bit will indicate whether the clock is being
provided by the Timer1 oscillator or another source.
Timer1 can also be used to provide Real-Time Clock
(RTC) functionality to applications with only a minimal
addition of external components and code overhead.
PIC18F1230/1330
(1)
T1SYNC
R/W-0
x = Bit is unknown
TMR1CS
R/W-0
DS39758D-page 111
TMR1ON
R/W-0
bit 0