PIC18F86K90-I/PT Microchip Technology, PIC18F86K90-I/PT Datasheet - Page 49

• Manufacturer Part Number: PIC18F86K90-I/PT
• Description: 64kB Flash, 4kB RAM, 1kB EE, 16MIPS, NanoWatt XLP, LCD, 5V 80 TQFP 12x12x1mm TRA
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F86K90-I/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 64MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 24x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

3.7
In addition to the F
tor modes, the device clock in the PIC18F87K90 family
can also be configured to provide a reference clock out-
put signal to a port pin. This feature is available in all
oscillator configurations and allows the user to select a
greater range of clock submultiples to drive external
devices in the application.
This reference clock output is controlled by the
REFOCON register (Register 3-4). Setting the ROON
bit (REFOCON<7>) makes the clock signal available
on the REFO (RE3) pin. The RODIV<3:0> bits enable
the selection of 16 different clock divider options.
REGISTER 3-4:
 2010 Microchip Technology Inc.
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
bit 3-0
Note 1:
ROON
R/W-0
Reference Clock Output
For ROSEL (REFOCON<4>), the primary oscillator is only available when configured as default via the
FOSC settings (regardless of whether the device is in Sleep mode).
ROON: Reference Oscillator Output Enable bit
1 = Reference oscillator output is available on REFO pin
0 = Reference oscillator output is disabled
Unimplemented: Read as ‘0’
ROSSLP: Reference Oscillator Output Stop in Sleep bit
1 = Reference oscillator continues to run in Sleep
0 = Reference oscillator is disabled in Sleep
ROSEL: Reference Oscillator Source Select bit
1 = Primary oscillator (EC or HS) is used as the base clock
0 = System clock is used as the base clock; base clock reflects any clock switching of the device
RODIV<3:0>: Reference Oscillator Divisor Select bits
1111 = Base clock value divided by 32,768
1110 = Base clock value divided by 16,384
1101 = Base clock value divided by 8,192
1100 = Base clock value divided by 4,096
1011 = Base clock value divided by 2,048
1010 = Base clock value divided by 1,024
1001 = Base clock value divided by 512
1000 = Base clock value divided by 256
0111 = Base clock value divided by 128
0110 = Base clock value divided by 64
0101 = Base clock value divided by 32
0100 = Base clock value divided by 16
0011 = Base clock value divided by 8
0010 = Base clock value divided by 4
0001 = Base clock value divided by 2
0000 = Base clock value
OSC
U-0
—
/4 clock output in certain oscilla-
REFOCON: REFERENCE OSCILLATOR CONTROL REGISTER
W = Writable bit
‘1’ = Bit is set
ROSSLP
R/W-0
ROSEL
R/W-0
Preliminary
(1)
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
PIC18F87K90 FAMILY
RODIV3
(1)
R/W-0
The ROSSLP and ROSEL bits (REFOCON<5:4>) con-
trol the availability of the reference output during Sleep
mode. The ROSEL bit determines if the oscillator on
OSC1 and OSC2, or the current system clock source,
is used for the reference clock output. The ROSSLP bit
determines if the reference source is available on RE3
when the device is in Sleep mode.
To use the reference clock output in Sleep mode, both
the ROSSLP and ROSEL bits must be set. The device
clock must also be configured for an EC or HS mode;
otherwise, the oscillator on OSC1 and OSC2 will be
powered down when the device enters Sleep mode.
Clearing the ROSEL bit allows the reference output
frequency to change as the system clock changes
during any clock switches.
RODIV2
R/W-0
x = Bit is unknown
RODIV1
R/W-0
DS39957B-page 49
RODIV0
R/W-0
bit 0