PIC18F45K22-I/P Microchip Technology Inc., PIC18F45K22-I/P Datasheet - Page 162

• Manufacturer Part Number: PIC18F45K22-I/P
• Description: 40 PDIP .600in TUBE, 32KB, Flash, 1536bytes-RAM, 8-bit Family, nanoWatt XLP
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F45K22-I/P

• A/d Inputs: 28-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 16 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 35
• Interface: I2C/SPI/UART/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 32K Bytes
• Ram Size: 1.5K Bytes
• Speed: 64 MHz
• Temperature Range: –40 to 125 °C
• Timers: 3-8-bit, 4-16-bit
• Voltage, Range: 1.8-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18(L)F2X/4XK22
12.1
The Timer1/3/5 module is a 16-bit incrementing
counter which is accessed through the TMRxH:TMRxL
register pair. Writes to TMRxH or TMRxL directly
update the counter.
When used with an internal clock source, the module is
a timer and increments on every instruction cycle.
When used with an external clock source, the module
can be used as either a timer or counter and
increments on every selected edge of the external
source.
Timer1/3/5 is enabled by configuring the TMRxON and
TMRxGE bits in the TxCON and TxGCON registers,
respectively.
selections.
TABLE 12-1:
12.2
The TMRxCS<1:0> and TxSOSCEN bits of the TxCON
register are used to select the clock source for
Timer1/3/5. The dedicated Secondary Oscillator circuit
can be used as the clock source for Timer1, Timer3 and
Timer5, simultaneously. Any of the TxSOSCEN bits will
enable the Secondary Oscillator circuit and select it as
the clock source for that particular timer.
displays the clock source selections.
TABLE 12-2:
DS41412D-page 162
TMRxCS1
TMRxON
0
0
1
1
0
0
1
1
Timer1/3/5 Operation
Clock Source Selection
Table 12-1
TIMER1/3/5 ENABLE
SELECTIONS
CLOCK SOURCE SELECTIONS
TMRxCS0
TMRxGE
displays the Timer1/3/5 enable
0
1
0
1
1
0
0
0
Off
Off
Always On
Count Enabled
TxSOSCEN
Timer1/3/5
Operation
Table 12-2
x
x
0
1
Preliminary
System Clock (F
Instruction Clock (F
External Clocking on TxCKI Pin
Osc.Circuit On SOSCI/SOSCO Pins
12.2.1
When the internal clock source is selected the
TMRxH:TMRxL register pair will increment on multiples
of F
When the F
Timer1/3/5 register value will increment by four counts
every instruction clock cycle. Due to this condition, a
2 LSB error in resolution will occur when reading the
Timer1/3/5 value. To utilize the full resolution of
Timer1/3/5, an asynchronous input signal must be used
to gate the Timer1/3/5 clock input.
The following asynchronous sources may be used:
• Asynchronous event on the TxG pin to Timer1/3/5
• C1 or C2 comparator input to Timer1/3/5 Gate
12.2.2
When the external clock source is selected, the
Timer1/3/5 module may work as a timer or a counter.
When enabled to count, Timer1/3/5 is incremented on
the rising edge of the external clock input of the TxCKI
pin. This external clock source can be synchronized to
the microcontroller system clock or it can run
asynchronously.
When used as a timer with a clock oscillator, an
external 32.768 kHz crystal can be used in conjunction
with the dedicated secondary internal oscillator circuit.
Gate
Note:
OSC
as determined by the Timer1/3/5 prescaler.
OSC
OSC
• Timer1/3/5 enabled after POR
• Write to TMRxH or TMRxL
• Timer1/3/5 is disabled
• Timer1/3/5 is disabled (TMRxON = 0)
INTERNAL CLOCK SOURCE
EXTERNAL CLOCK SOURCE
In Counter mode, a falling edge must be
registered by the counter prior to the first
incrementing rising edge after any one or
more of the following conditions:
OSC
)
when TxCKI is high then Timer1/3/5
is enabled (TMRxON=1) when TxCKI
is low.
/4)
Clock Source
internal clock source is selected, the
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