PIC18C801-I/L Microchip Technology, PIC18C801-I/L Datasheet - Page 179

• Manufacturer Part Number: PIC18C801-I/L
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,LDCC,84PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Cr

Specifications of PIC18C801-I/L

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 37
• Program Memory Type: ROMless
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 84-PLCC
• Processor Series: PIC18C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 1.5 KB
• Interface Type: 3-Wire, I2C, SPI, USART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 47
• Number Of Timers: 1 x 16 bit
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: DV164005, ICE4000, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164310 - MODULE SKT FOR PM3 84PLCCXLT84L1 - SOCKET TRANSITION ICE 84PLCCAC174012 - MODULE SKT PROMATEII 84PLCC
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / Rohs Status: Details
• Other names: PIC18C801-I/LR; PIC18C801-I/LR; PIC18C801I/L

16.1
The BRG supports both the Asynchronous and Syn-
chronous modes of the USART. It is a dedicated 8-bit
baud rate generator. The SPBRG register controls the
period of a free running 8-bit timer. In Asynchronous
mode, bit BRGH (TXSTA register) also controls the
baud rate. In Synchronous mode, bit BRGH is ignored.
Table 16-1 shows the formula for computation of the
baud rate for different USART modes, which only apply
in Master mode (internal clock).
Given the desired baud rate and F
integer value for the SPBRG register can be calculated
using the formula in Table 16-1. From this, the error in
baud rate can be determined.
EXAMPLE 16-1:
TABLE 16-1:
TABLE 16-2:
Desired Baud Rate
Solving for X:
Calculated Baud Rate
Error
Legend: X = value in SPBRG (0 to 255)
Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used by the BRG.
SPBRG
RCSTA
TXSTA
2001 Microchip Technology Inc.
Name
SYNC
0
1
USART Baud Rate Generator
(BRG)
X
X
X
Baud Rate Generator Register
CSRC
SPEN
Bit 7
BAUD RATE FORMULA
REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR
(Asynchronous) Baud Rate = F
(Synchronous) Baud Rate = F
CALCULATING BAUD RATE ERROR
Bit 6
TX9
RX9
=
=
=
=
=
=
=
=
=
BRGH = 0 (Low Speed)
SREN
TXEN
Bit 5
F
( (F
((16000000 / 9600) / 64) - 1
[25.042] = 25
16000000 / (64 (25 + 1))
9615
(Calculated Baud Rate - Desired Baud Rate)
(9615 - 9600) / 9600
0.16%
OSC
OSC
OSC
/ (64 (X + 1))
, the nearest
/ Desired Baud Rate) / 64 ) - 1
SYNC
CREN
Bit 4
Advance Information
Desired Baud Rate
ADDEN
Bit 3
OSC
OSC
—
/(64(X+1))
/(4(X+1))
BRGH
FERR
Bit 2
Example 16-1 shows the calculation of the baud rate
error for the following conditions:
It may be advantageous to use the high baud rate
(BRGH = 1), even for slower baud clocks. This is
because the F
baud rate error in some cases.
Writing a new value to the SPBRG register causes the
BRG timer to be reset (or cleared). This ensures the
BRG does not wait for a timer overflow before output-
ting the new baud rate.
16.1.1
The data on the RC7/RX/DT pin is sampled three times
by a majority detect circuit to determine if a high or a
low level is present at the RX pin.
OERR
TRMT
F
Desired Baud Rate = 9600
BRGH = 0
SYNC = 0
Bit 1
OSC
SAMPLING
= 16 MHz
OSC
PIC18C601/801
TX9D
RX9D
Bit 0
/(16(X + 1)) equation can reduce the
Baud Rate = F
BRGH = 1 (High Speed)
0000 -010
0000 000x
0000 0000
Value on
POR,
BOR
NA
OSC
DS39541A-page 179
/(16(X+1))
Value on all
0000 -010
0000 000x
0000 0000
RESETS
other