PIC18F86J50-I/PT Microchip Technology, PIC18F86J50-I/PT Datasheet - Page 198

• Manufacturer Part Number: PIC18F86J50-I/PT
• Description: IC PIC MCU FLASH 32KX16 80TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F86J50-I/PT

• Core Size: 8-Bit
• Program Memory Size: 64KB (32K x 16)
• Oscillator Type: Internal
• Core Processor: PIC
• Speed: 48MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 65
• Program Memory Type: FLASH
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 12x10b
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TFQFP
• Controller Family/series: PIC18
• No. Of I/o's: 65
• Ram Memory Size: 3904Byte
• Cpu Speed: 48MHz
• No. Of Timers: 5
• No. Of: RoHS Compliant
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3904 B
• Interface Type: I2C, MSSP, SPI, EUSART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 65
• Number Of Timers: 5
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DV164136, DM183022, DM183032
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 12 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC162087 - HEADER MPLAB ICD2 18F87J50 68/84MA180021 - MODULE PLUG-IN 18F87J50 FS USBAC164328 - MODULE SKT FOR 80TQFP
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

PIC18F87J50 FAMILY
If a high-speed circuit must be located near the oscilla-
tor (such as the ECCP1 pin in Output Compare or PWM
mode, or the primary oscillator using the OSC2 pin), a
grounded guard ring around the oscillator circuit, as
shown in Figure 13-4, may be helpful when used on a
single-sided PCB or in addition to a ground plane.
FIGURE 13-4:
13.4
The TMR1 register pair (TMR1H:TMR1L) increments
from 0000h to FFFFh and rolls over to 0000h. The
Timer1 interrupt, if enabled, is generated on overflow
which is latched in interrupt flag bit, TMR1IF
(PIR1<0>). This interrupt can be enabled or disabled
by setting or clearing the Timer1 Interrupt Enable bit,
TMR1IE (PIE1<0>).
13.5
If ECCP1 or ECCP2 is configured to use Timer1 and to
generate a Special Event Trigger in Compare mode
(CCPxM3:CCPxM0 = 1011), this signal will reset
Timer3. The trigger from ECCP2 will also start an A/D
conversion if the A/D module is enabled (see
Section 18.2.1 “Special Event Trigger” for more
information).
The module must be configured as either a timer or a
synchronous counter to take advantage of this feature.
When used this way, the CCPRxH:CCPRxL register
pair effectively becomes a period register for Timer1.
If Timer1 is running in Asynchronous Counter mode,
this Reset operation may not work.
In the event that a write to Timer1 coincides with a
Special Event Trigger, the write operation will take
precedence.
DS39775C-page 198
Note: Not drawn to scale.
Timer1 Interrupt
Resetting Timer1 Using the ECCP
Special Event Trigger
OSCILLATOR CIRCUIT
WITH GROUNDED
GUARD RING
OSC1
RC0
V
V
OSC2
RC1
RC2
DD
SS
13.6
Adding an external LP oscillator to Timer1 (such as the
one described in Section 13.3 “Timer1 Oscillator”)
gives users the option to include RTC functionality to
their applications. This is accomplished with an inex-
pensive watch crystal to provide an accurate time base
and several lines of application code to calculate the
time. When operating in Sleep mode and using a
battery or supercapacitor as a power source, it can
completely eliminate the need for a separate RTC
device and battery backup.
The application code routine, RTCisr, shown in
Example 13-1, demonstrates a simple method to
increment a counter at one-second intervals using an
Interrupt Service Routine. Incrementing the TMR1
register pair to overflow triggers the interrupt and calls
the routine which increments the seconds counter by
one. Additional counters for minutes and hours are
incremented as the previous counter overflows.
Since the register pair is 16 bits wide, counting up to
overflow the register directly from a 32.768 kHz clock
would take 2 seconds. To force the overflow at the
required one-second intervals, it is necessary to pre-
load it. The simplest method is to set the MSb of
TMR1H with a BSF instruction. Note that the TMR1L
register is never preloaded or altered; doing so may
introduce cumulative error over many cycles.
For this method to be accurate, Timer1 must operate in
Asynchronous mode and the Timer1 overflow interrupt
must be enabled (PIE1<0> = 1) as shown in the
routine, RTCinit. The Timer1 oscillator must also be
enabled and running at all times.
13.7
Following a Timer1 interrupt and an update to the
TMR1 registers, the Timer1 module uses a falling edge
on its clock source to trigger the next register update on
the rising edge. If the update is completed after the
clock input has fallen, the next rising edge will not be
counted.
If the application can reliably update TMR1 before the
timer input goes low, no additional action is needed.
Otherwise, an adjusted update can be performed
following a later Timer1 increment. This can be done by
monitoring TMR1L within the interrupt routine until it
increments, and then updating the TMR1H:TMR1L reg-
ister pair while the clock is low, or one-half of the period
of the clock source. Assuming that Timer1 is being
used as a Real-Time Clock, the clock source is a
32.768 kHz crystal oscillator. In this case, one-half
period of the clock is 15.25 μs.
Note:
Using Timer1 as a Real-Time Clock
Considerations in Asynchronous
Counter Mode
The Special Event Triggers from the
ECCPx module will not set the TMR1IF
interrupt flag bit (PIR1<0>).
© 2009 Microchip Technology Inc.