PIC18F65J15T-I/PT Microchip Technology, PIC18F65J15T-I/PT Datasheet - Page 245

• Manufacturer Part Number: PIC18F65J15T-I/PT
• Description: IC PIC MCU FLASH 24KX16 64TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F65J15T-I/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 50
• Program Memory Size: 48KB (24K x 16)
• Program Memory Type: FLASH
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TFQFP
• For Use With: MA180015 - MODULE PLUG-IN 18F87J10 FOR HPCAC162062 - HEADER INTRFC MPLAB ICD2 64/80PAC164327 - MODULE SKT FOR 64TQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: PIC18F65J15T-I/PT; PIC18F65J15T-I/PTTR

20.1
The BRG is a dedicated 8-bit or 16-bit generator that
supports both the Asynchronous and Synchronous
modes of the EUSART. By default, the BRG operates
in 8-bit mode; setting the BRG16 bit (BAUDCONx<3>)
selects 16-bit mode.
The SPBRGHx:SPBRGx register pair controls the period
of a free-running timer. In Asynchronous mode, bits
BRGH (TXSTAx<2>) and BRG16 (BAUDCONx<3>) also
control the baud rate. In Synchronous mode, BRGH is
ignored. Table 20-1 shows the formula for computation of
the baud rate for different EUSART modes which only
apply in Master mode (internally generated clock).
Given the desired baud rate and F
integer value for the SPBRGHx:SPBRGx registers can
be calculated using the formulas in Table 20-1. From this,
the error in baud rate can be determined. An example
calculation is shown in Example 20-1. Typical baud rates
and error values for the various Asynchronous modes
are shown in Table 20-2. It may be advantageous to use
TABLE 20-1:
© 2009 Microchip Technology Inc.
Legend: x = Don’t care, n = value of SPBRGHx:SPBRGx register pair
SYNC
0
0
0
0
1
1
Baud Rate Generator (BRG)
Configuration Bits
BAUD RATE FORMULAS
BRG16
0
0
1
1
0
1
BRGH
0
1
0
1
x
x
OSC
, the nearest
BRG/EUSART Mode
16-Bit/Asynchronous
16-Bit/Asynchronous
16-Bit/Synchronous
8-Bit/Asynchronous
8-Bit/Asynchronous
8-Bit/Synchronous
PIC18F87J10 FAMILY
the high baud rate (BRGH = 1) or the 16-bit BRG to
reduce the baud rate error, or achieve a slow baud rate
for a fast oscillator frequency.
Writing a new value to the SPBRGHx:SPBRGx regis-
ters causes the BRG timer to be reset (or cleared). This
ensures the BRG does not wait for a timer overflow
before outputting the new baud rate.
20.1.1
The device clock is used to generate the desired baud
rate. When one of the power-managed modes is
entered, the new clock source may be operating at a
different frequency. This may require an adjustment to
the value in the SPBRGx register pair.
20.1.2
The data on the RXx pin (either RC7/RX1/DT1 or
RG2/RX2/DT2) is sampled three times by a majority
detect circuit to determine if a high or a low level is
present at the RXx pin.
OPERATION IN POWER-MANAGED
MODES
SAMPLING
Baud Rate Formula
F
F
F
OSC
OSC
OSC
/[64 (n + 1)]
/[16 (n + 1)]
/[4 (n + 1)]
DS39663F-page 243