PIC16F818-I/SO Microchip Technology Inc., PIC16F818-I/SO Datasheet - Page 59
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PIC16F818-I/SO
Manufacturer Part Number
PIC16F818-I/SO
Description
18 PIN, 1.75 KB FLASH, 128 RAM, 16 I/O
Manufacturer
Microchip Technology Inc.
Datasheet
1.PIC16F818-ISO.pdf
(176 pages)
Specifications of PIC16F818-I/SO
A/d Inputs
5-Channel, 10-Bit
Cpu Speed
5 MIPS
Eeprom Memory
128 Bytes
Input Output
16
Interface
I2C/SPI
Memory Type
Flash
Number Of Bits
8
Package Type
18-pin SOIC
Programmable Memory
1.75K Bytes
Ram Size
128 Bytes
Speed
20 MHz
Timers
2-8-bit, 1-16-bit
Voltage, Range
2-5.5 V
Lead Free Status / Rohs Status
RoHS Compliant part
Electrostatic Device
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
PIC16F818-I/SO
Manufacturer:
MICROCHIP
Quantity:
3 290
Part Number:
PIC16F818-I/SO
Manufacturer:
MICROCHIP/微芯
Quantity:
20 000
7.0
The Timer1 module is a 16-bit timer/counter consisting
of two 8-bit registers (TMR1H and TMR1L) which are
readable and writable. The TMR1 register pair
(TMR1H:TMR1L) increments from 0000h to FFFFh
and rolls over to 0000h. The TMR1 interrupt, if enabled,
is generated on overflow which is latched in interrupt
flag bit, TMR1IF (PIR1<0>). This interrupt can be
enabled/disabled by setting/clearing TMR1 Interrupt
Enable bit, TMR1IE (PIE1<0>).
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.
7.1
Timer1 can operate in one of three modes:
• as a timer
• as a synchronous counter
• as an asynchronous counter
REGISTER 7-1:
2004 Microchip Technology Inc.
TIMER1 MODULE
Timer1 Operation
bit 7-6
bit 5-4
bit 3
bit 2
bit 1
bit 0
T1CON: TIMER1 CONTROL REGISTER (ADDRESS 10h)
Unimplemented: Read as ‘0’
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 Control bit
1 = Oscillator is enabled
0 = Oscillator is shut-off (the oscillator inverter is turned off to eliminate power drain)
T1SYNC: Timer1 External Clock Input Synchronization Control bit
TMR1CS = 1:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
TMR1CS = 0:
This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.
TMR1CS: Timer1 Clock Source Select bit
1 = External clock from pin RB6/T1OSO/T1CKI/PGC (on the rising edge)
0 = Internal clock (F
TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1
bit 7
Legend:
R = Readable bit
-n = Value at POR
U-0
—
U-0
—
OSC
T1CKPS1
R/W-0
/4)
W = Writable bit
‘1’ = Bit is set
T1CKPS0
R/W-0
The operating mode is determined by the clock select
bit, TMR1CS (T1CON<1>).
In Timer mode, Timer1 increments every instruction
cycle. In Counter mode, it increments on every rising
edge of the external clock input.
Timer1 can be enabled/disabled by setting/clearing
control bit, TMR1ON (T1CON<0>).
Timer1 also has an internal “Reset input”. This Reset
can be generated by the CCP1 module as the special
event trigger (see Section 9.1 “Capture Mode”).
Register 7-1 shows the Timer1 Control register.
When the Timer1 oscillator is enabled (T1OSCEN is
set), the RB6/T1OSO/T1CKI/PGC and RB7/T1OSI/
PGD pins become inputs. That is, the TRISB<7:6>
value is ignored and these pins read as ‘0’.
Additional information on timer modules is available in
the “PICmicro
Manual” (DS33023).
T1OSCEN T1SYNC TMR1CS TMR1ON
R/W-0
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
®
PIC16F818/819
Mid-Range MCU Family Reference
R/W-0
x = Bit is unknown
R/W-0
DS39598E-page 57
R/W-0
bit 0