PIC18F87J50-I/PT Microchip Technology, PIC18F87J50-I/PT Datasheet - Page 40

• Manufacturer Part Number: PIC18F87J50-I/PT
• Description: IC PIC MCU FLASH 64KX16 80TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F87J50-I/PT

• Program Memory Type: FLASH
• Program Memory Size: 128KB (64K x 16)
• Package / Case: 80-TFQFP
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 65
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3936 B
• Interface Type: I2C, MSSP, SPI, EUSART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 66
• Number Of Timers: 5
• Maximum Operating Temperature: + 100 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, DM183032, DM183022, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 12 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC162087 - HEADER MPLAB ICD2 18F87J50 68/84MA180021 - MODULE PLUG-IN 18F87J50 FS USBAC164328 - MODULE SKT FOR 80TQFP
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F87J50 FAMILY
REGISTER 2-1:
2.3
When the PIC18F87J10 family is used for USB
connectivity, a 6 MHz or 48 MHz clock must be
provided to the USB module for operation in either
Low-Speed or Full-Speed modes, respectively. This
may require some forethought in selecting an oscillator
frequency and programming the device.
The full range of possible oscillator configurations
compatible with USB operation is shown in Table 2-5.
2.3.1
The USB clock for Low-Speed mode is derived from the
primary oscillator or from the 96 MHz PLL. In order to
operate the USB module in Low-Speed mode, a 6 MHz
clock must be provided to the USB module. Due to the
DS39775C-page 40
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6
bit 5-0
INTSRC
R/W-0
Oscillator Settings for USB
LOW-SPEED OPERATION
INTSRC: Internal Oscillator Low-Frequency Source Select bit
1 = 31.25 kHz device clock derived from 8 MHz INTOSC source (divide-by-256 enabled)
0 = 31 kHz device clock derived directly from INTRC internal oscillator
PLLEN: Frequency Multiplier Enable bit
1 = 96 MHz PLL is enabled
0 = 96 MHz PLL is disabled
TUN5:TUN0: Frequency Tuning bits
011111 = Maximum frequency
011110
•
•
•
000001
000000 = Center frequency. Oscillator module is running at the calibrated frequency.
111111
•
•
100000 = Minimum frequency
PLLEN
R/W-0
OSCTUNE: OSCILLATOR TUNING REGISTER
W = Writable bit
‘1’ = Bit is set
R/W-0
TUN5
•
•
•
•
•
R/W-0
TUN4
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
R/W-0
TUN3
way the clock dividers have been implemented in the
PIC18F87J50 family, the microcontroller core must run
at 24 MHz in order for the USB module to get the 6 MHz
clock needed for low-speed USB operation. Several
clocking schemes could be used to meet these two
required conditions. See Table 2-4 and Table 2-5 for
possible combinations which can be used for
low-speed USB operation.
TABLE 2-4:
Clock
Input
48
24
Clock
CPU
24
24
R/W-0
TUN2
CLOCK FOR LOW-SPEED
USB
CPDIV<1:0>
© 2009 Microchip Technology Inc.
<1, 1>
<1, 0>
x = Bit is unknown
R/W-0
TUN1
48/8 = 6 MHz
24/4 = 6 MHz
USB Clock
R/W-0
TUN0
bit 0