PIC16F684-E/P Microchip Technology Inc., PIC16F684-E/P Datasheet - Page 51

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PIC16F684-E/P

Manufacturer Part Number
PIC16F684-E/P
Description
14 PIN, 3.5 KB FLASH, 128 RAM, 12 I/O
Manufacturer
Microchip Technology Inc.
Datasheet

Specifications of PIC16F684-E/P

A/d Inputs
8-Channel, 10-Bit
Comparators
2
Cpu Speed
5 MIPS
Eeprom Memory
256 Bytes
Input Output
12
Memory Type
Flash
Number Of Bits
8
Package Type
14-pin PDIP
Programmable Memory
3.5K 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
6.6
Timer1 gate source is software configurable to be the
T1G pin or the output of Comparator 2. This allows the
device to directly time external events using T1G or
analog events using Comparator 2. See the CMCON1
register (Register 8-2) for selecting the Timer1 gate
source. This feature can simplify the software for a
Delta-Sigma A/D converter and many other applications.
For more information on Delta-Sigma A/D converters,
see the Microchip web site (www.microchip.com).
Timer1 gate can be inverted using the T1GINV bit of
the T1CON register, whether it originates from the T1G
pin or Comparator 2 output. This configures Timer1 to
measure either the active-high or active-low time
between events.
6.7
The Timer1 register pair (TMR1H:TMR1L) increments
to FFFFh and rolls over to 0000h. When Timer1 rolls
over, the Timer1 interrupt flag bit of the PIR1 register is
set. To enable the interrupt on rollover, you must set
these bits:
• TMR1ON bit or the T1CON register
• TMR1IE bit of the PIE1 register
• PEIE bit of the INTCON register
• GIE bit of the INTCON register
The interrupt is cleared by clearing the TMR1IF bit in
the Interrupt Service Routine.
6.8
Timer1 can only operate during Sleep when setup in
Asynchronous Counter mode. In this mode, an external
crystal or clock source can be used to increment the
counter. To set up the timer to wake the device:
• TMR1ON bit of the T1CON register must be set
• TMR1IE bit of the PIE1 register must be set
• PEIE bit of the INTCON register must be set
• T1SYNC bit of the T1CON register
• TMR1CS bit of the T1CON register
• T1OSCEN bit of the T1CON register (can be set)
The device will wake-up on an overflow and execute
the next instruction. If the GIE bit of the INTCON
register is set, the device will call the Interrupt Service
Routine (0004h).
© 2006 Microchip Technology Inc.
Note:
Note:
Timer1 Gate
Timer1 Interrupt
Timer1 Operation During Sleep
TMR1GE bit of the T1CON register must
be set to use either T1G or C2OUT as the
Timer1 gate source. See the CMCON1
register (Register 8-2) for more informa-
tion on selecting the Timer1 gate source.
The TMR1H:TTMR1L register pair and the
TMR1IF bit should be cleared before
enabling interrupts.
6.9
The ECCP module uses the TMR1H:TMR1L register
pair as the time base when operating in Capture or
Compare mode.
In Capture mode, the value in the TMR1H:TMR1L
register pair is copied into the CCPR1H:CCPR1L
register pair on a configured event.
In Compare mode, an event is triggered when the value
CCPR1H:CCPR1L register pair matches the value in
the TMR1H:TMR1L register pair. This event can be a
Special Event Trigger.
For more information, see Section 11.0 “Enhanced
Capture/Compare/PWM (With Auto-Shutdown and
Dead Band) Module”.
6.10
When the ECCP is configured to trigger a special
event, the trigger will clear the TMR1H:TMR1L register
pair. This special event does not cause a Timer1
interrupt. The ECCP module may still be configured to
generate a ECCP interrupt.
In this mode of operation, the CCPR1H:CCPR1L
register pair effectively becomes the period register for
Timer1.
Timer1 should be synchronized to the F
the Special Event Trigger. Asynchronous operation of
Timer1 can cause a Special Event Trigger to be
missed.
In the event that a write to TMR1H or TMR1L coincides
with a Special Event Trigger from the ECCP, the write
will take precedence.
For more information, see Section 11.2.4 “Special
Event Trigger”.
6.11
The same clock used to increment Timer1 can also be
used to synchronize the comparator output. This
feature is enabled in the Comparator module.
When using the comparator for Timer1 gate, the
comparator output should be synchronized to Timer1.
This ensures Timer1 does not miss an increment if the
comparator changes.
For more information, see Section 8.9 “Synchronizing
Comparator C2 Output to Timer1”.
ECCP Capture/Compare Time Base
ECCP Special Event Trigger
Comparator Synchronization
PIC16F684
DS41202D-page 49
OSC
to utilize

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