PIC18F45K80-I Datasheet, PDF (338/622 Pages) Microchip Technology – 28/40/44/64-Pin, Enhanced Flash Microcontrollers with ECAN and nanoWatt XLP Technology

PIC18F66K80 FAMILY
EXAMPLE 22-1: CALCULATING BAUD RATE ERROR
For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, and 8-bit BRG:
Desired Baud Rate = FOSC/(64 ([SPBRGHx:SPBRGx] + 1))
Solving for SPBRGHx:SPBRGx:
X = ((FOSC/Desired Baud Rate)/64) – 1
= ((16000000/9600)/64) – 1
= [25.042] = 25
Calculated Baud Rate = 16000000/(64 (25 + 1))
= 9615
Error = (Calculated Baud Rate – Desired Baud Rate)/Desired Baud Rate
= (9615 – 9600)/9600 = 0.16%
TABLE 22-3: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
TXSTA1
CSRC
TX9
TXEN
SYNC
SENDB BRGH
TRMT
RCSTA1
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
BAUDCON1
ABDOVF RCIDL
RXDTP TXCKP
BRG16
—
WUE
SPBRGH1
EUSART1 Baud Rate Generator Register High Byte
SPBRG1
EUSART1 Baud Rate Generator Register
TXSTA2
CSRC
TX9
TXEN
SYNC
SENDB BRGH
TRMT
RCSTA2
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
BAUDCON2
ABDOVF RCIDL
RXDTP TXCKP
BRG16
—
WUE
SPBRGH2
EUSART2 Baud Rate Generator Register High Byte
SPBRG2
EUSART2 Baud Rate Generator Register Low Byte
PMD0
CCP5MD CCP4MD CCP3MD CCP2MD CCP1MD UART2MD UART1MD
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the BRG.
TX9D
RX9D
ABDEN
TX9D
RX9D
ABDEN
SSPMD
DS39977F-page 338
 2010-2012 Microchip Technology Inc.