PIC18F87J50-I/PT Microchip Technology, PIC18F87J50-I/PT Datasheet - Page 293

• Manufacturer Part Number: PIC18F87J50-I/PT
• Description: IC PIC MCU FLASH 64KX16 80TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F87J50-I/PT

• Program Memory Type: FLASH
• Program Memory Size: 128KB (64K x 16)
• Package / Case: 80-TFQFP
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 65
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3936 B
• Interface Type: I2C, MSSP, SPI, EUSART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 66
• Number Of Timers: 5
• Maximum Operating Temperature: + 100 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, DM183032, DM183022, DV164136
• 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: Lead free / RoHS Compliant

20.2.4.1
Since auto-wake-up functions by sensing rising edge
transitions on RXx/DTx, information with any state
changes before the Stop bit may signal a false
End-of-Character (EOC) and cause data or framing
errors. To work properly, therefore, the initial character
in the transmission must be all ‘0’s. This can be 00h (8
bytes) for standard RS-232 devices or 000h (12 bits) for
LIN bus.
Oscillator start-up time must also be considered,
especially in applications using oscillators with longer
start-up intervals (i.e., HS or HSPLL mode). The Sync
Break (or Wake-up Signal) character must be of
sufficient length and be followed by a sufficient interval
to allow enough time for the selected oscillator to start
and provide proper initialization of the EUSART.
FIGURE 20-8:
FIGURE 20-9:
© 2009 Microchip Technology Inc.
Note 1:
RXx/DTx Line
RXx/DTx Line
Note 1:
WUE bit
WUE bit
2:
RCxIF
OSC1
RCxIF
OSC1
The EUSART remains in Idle while the WUE bit is set.
If the wake-up event requires long oscillator warm-up time, the auto-clear of the WUE bit can occur before the oscillator is ready. This
sequence should not depend on the presence of Q clocks.
The EUSART remains in Idle while the WUE bit is set.
(1)
(2)
Special Considerations Using
Auto-Wake-up
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Bit set by user
Bit set by user
SLEEP Command Executed
AUTO-WAKE-UP BIT (WUE) TIMINGS DURING NORMAL OPERATION
AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP
Q1
Sleep Ends
PIC18F87J50 FAMILY
20.2.4.2
The timing of WUE and RCxIF events may cause some
confusion when it comes to determining the validity of
received data. As noted, setting the WUE bit places the
EUSART in an Idle mode. The wake-up event causes a
receive interrupt by setting the RCxIF bit. The WUE bit
is cleared after this when a rising edge is seen on
RXx/DTx. The interrupt condition is then cleared by
reading the RCREGx register. Ordinarily, the data in
RCREGx will be dummy data and should be discarded.
The fact that the WUE bit has been cleared (or is still
set) and the RCxIF flag is set should not be used as an
indicator of the integrity of the data in RCREGx. Users
should consider implementing a parallel method in
firmware to verify received data integrity.
To assure that no actual data is lost, check the RCIDL
bit to verify that a receive operation is not in process. If
a receive operation is not occurring, the WUE bit may
then be set just prior to entering the Sleep mode.
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Cleared due to user read of RCREGx
Cleared due to user read of RCREGx
Special Considerations Using
the WUE Bit
Note 1
DS39775C-page 293
Auto-Cleared
Auto-Cleared