PIC18F67K22-I/MR Microchip Technology, PIC18F67K22-I/MR Datasheet - Page 343

• Manufacturer Part Number: PIC18F67K22-I/MR
• Description: 128kB Flash, 4kB RAM, 1kB EE, NanoWatt XLP, GP 64 QFN 9x9x0.9mm TUBE
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F67K22-I/MR

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 64MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 16x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VFQFN Exposed Pad
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

22.2.4.2
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.
FIGURE 22-8:
FIGURE 22-9:
 2009-2011 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
the WUE Bit
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
PIC18F87K22 FAMILY
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 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
Note 1
DS39960D-page 343
Auto-Cleared
Auto-Cleared