Microchip Technology DM163025-1 Hoja De Datos
PIC18(L)F2X/45K50
DS30684A-page 276
2012 Microchip Technology Inc.
17.1.2.9
Asynchronous Reception Setup:
1.
Initialize the SPBRGHx:SPBRGx register pair
and the BRGH and BRG16 bits to achieve the
desired baud rate (see
and the BRGH and BRG16 bits to achieve the
desired baud rate (see
).
2.
Set the RX/DT and TX/CK TRIS controls to ‘1’.
3.
Enable the serial port by setting the SPEN bit
and the RX/DT pin TRIS bit. The SYNC bit must
be clear for asynchronous operation.
and the RX/DT pin TRIS bit. The SYNC bit must
be clear for asynchronous operation.
4.
If interrupts are desired, set the RCIE interrupt
enable bit and set the GIE/GIEH and PEIE/GIEL
bits of the INTCON register.
enable bit and set the GIE/GIEH and PEIE/GIEL
bits of the INTCON register.
5.
If 9-bit reception is desired, set the RX9 bit.
6.
Set the RXDTP if inverted receive polarity is
desired.
desired.
7.
Enable reception by setting the CREN bit.
8.
The RCIF interrupt flag bit will be set when a
character is transferred from the RSR to the
receive buffer. An interrupt will be generated if
the RCIE interrupt enable bit was also set.
character is transferred from the RSR to the
receive buffer. An interrupt will be generated if
the RCIE interrupt enable bit was also set.
9.
Read the RCSTAx register to get the error flags
and, if 9-bit data reception is enabled, the ninth
data bit.
and, if 9-bit data reception is enabled, the ninth
data bit.
10. Get the received eight Least Significant data bits
from the receive buffer by reading the RCREGx
register.
register.
11. If an overrun occurred, clear the OERR flag by
clearing the CREN receiver enable bit.
17.1.2.10
9-bit Address Detection Mode Setup
This mode would typically be used in RS-485 systems.
To set up an Asynchronous Reception with Address
Detect Enable:
1.
To set up an Asynchronous Reception with Address
Detect Enable:
1.
Initialize the SPBRGHx, SPBRGx register pair
and the BRGH and BRG16 bits to achieve the
desired baud rate (see
and the BRGH and BRG16 bits to achieve the
desired baud rate (see
2.
Set the RX/DT and TX/CK TRIS controls to ‘1’.
3.
Enable the serial port by setting the SPEN bit.
The SYNC bit must be clear for asynchronous
operation.
The SYNC bit must be clear for asynchronous
operation.
4.
If interrupts are desired, set the RCIE interrupt
enable bit and set the GIE/GIEH and PEIE/GIEL
bits of the INTCON register.
enable bit and set the GIE/GIEH and PEIE/GIEL
bits of the INTCON register.
5.
Enable 9-bit reception by setting the RX9 bit.
6.
Enable address detection by setting the ADDEN
bit.
bit.
7.
Set the RXDTP if inverted receive polarity is
desired.
desired.
8.
Enable reception by setting the CREN bit.
9.
The RCIF interrupt flag bit will be set when a
character with the ninth bit set is transferred
from the RSR to the receive buffer. An interrupt
will be generated if the RCIE interrupt enable bit
was also set.
character with the ninth bit set is transferred
from the RSR to the receive buffer. An interrupt
will be generated if the RCIE interrupt enable bit
was also set.
10. Read the RCSTAx register to get the error flags.
The ninth data bit will always be set.
11. Get the received eight Least Significant data bits
from the receive buffer by reading the RCREGx
register. Software determines if this is the
device’s address.
register. Software determines if this is the
device’s address.
12. If an overrun occurred, clear the OERR flag by
clearing the CREN receiver enable bit.
13. If the device has been addressed, clear the
ADDEN bit to allow all received data into the
receive buffer and generate interrupts.
receive buffer and generate interrupts.