PIC18F25K80 MICROCHIP [Microchip Technology], PIC18F25K80 Datasheet - Page 352

• Manufacturer Part Number: PIC18F25K80
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F66K80 FAMILY
22.3.2
The receiver block diagram is shown in
The data is received on the RXx pin and drives the data
recovery block. The data recovery block is actually a
high-speed shifter operating at x16 times the baud rate,
whereas the main receive serial shifter operates at the
bit rate or at F
in RS-232 systems.
To set up an Asynchronous Reception:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. If using interrupts, ensure that the GIE and PEIE
FIGURE 22-6:
DS39977C-page 352
Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
Enable the asynchronous serial port by clearing
bit, SYNC, and setting bit, SPEN.
If interrupts are desired, set enable bit, RCxIE.
If 9-bit reception is desired, set bit, RX9.
Enable the reception by setting bit, CREN.
Flag bit, RCxIF, will be set when reception is
complete and an interrupt will be generated if
enable bit, RCxIE, was set.
Read the RCSTAx register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
Read the 8-bit received data by reading the
RCREGx register.
If any error occurred, clear the error by clearing
enable bit, CREN.
bits (INTCON<7:6>) are set.
EUSART ASYNCHRONOUS
RECEIVER
RXx
BRG16
OSC
. This mode would typically be used
EUSART RECEIVE BLOCK DIAGRAM
SPBRGHx
Baud Rate Generator
x64 Baud Rate CLK
and Control
Pin Buffer
SPEN
SPBRGx
Figure
22-6.
Recovery
Interrupt
Preliminary
 64
 16
 4
Data
or
or
CREN
22.3.3
This mode would typically be used in RS-485 systems.
To set up an Asynchronous Reception with Address
Detect Enable:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. If any error occurred, clear the CREN bit.
11. If the device has been addressed, clear the
RX9
Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
Enable the asynchronous serial port by clearing
the SYNC bit and setting the SPEN bit.
If interrupts are required, set the RCEN bit and
select the desired priority level with the RCxIP bit.
Set the RX9 bit to enable 9-bit reception.
Set the ADDEN bit to enable address detect.
Enable reception by setting the CREN bit.
The RCxIF bit will be set when reception is
complete. The interrupt will be Acknowledged if
the RCxIE and GIE bits are set.
Read the RCSTAx register to determine if any
error occurred during reception, as well as read
bit 9 of data (if applicable).
Read RCREGx to determine if the device is
being addressed.
ADDEN bit to allow all received data into the
receive buffer and interrupt the CPU.
Stop
MSb
RCxIF
RCxIE
RX9D
SETTING UP 9-BIT MODE WITH
ADDRESS DETECT
(8)
OERR
7
RSR Register
RCREGx Register

 2011 Microchip Technology Inc.
8
Data Bus
1
FERR
0
LSb
Start
FIFO