PIC16F88-I/SO Microchip Technology Inc., PIC16F88-I/SO Datasheet - Page 40

• Manufacturer Part Number: PIC16F88-I/SO
• Description: 18 PIN, 7 KB FLASH, 368 RAM, 16 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F88-I/SO

• A/d Inputs: 7-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 16
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 18-pin SOIC
• Programmable Memory: 7K Bytes
• Ram Size: 368 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC16F87/88
4.5.1
Using the internal oscillator as the clock source can
eliminate the need for up to two external oscillator pins,
after which it can be used for digital I/O. Two distinct
configurations are available:
• In INTIO1 mode, the OSC2 pin outputs F
• In INTIO2 mode, OSC1 functions as RA7 and
REGISTER 4-1:
DS30487C-page 38
while OSC1 functions as RA7 for digital input and
output.
OSC2 functions as RA6, both for digital input and
output.
bit 7-6
bit 5-0
INTRC MODES
OSCTUNE: OSCILLATOR TUNING REGISTER (ADDRESS 90h)
Unimplemented: Read as ‘0’
TUN<5:0>: Frequency Tuning bits
011111 = Maximum frequency
011110 =
•
•
•
000001 =
000000 = Center frequency. Oscillator module is running at the calibrated frequency.
111111 =
•
•
•
100000 = Minimum frequency
bit 7
Legend:
R = Readable bit
-n = Value at POR
U-0
—
U-0
—
OSC
/4,
R/W-0
TUN5
W = Writable bit
‘1’ = Bit is set
R/W-0
TUN4
4.5.2
The internal oscillator’s output has been calibrated at the
factory but can be adjusted in the application. This is
done by writing to the OSCTUNE register (Register 4-1).
The tuning sensitivity is constant throughout the tuning
range. The OSCTUNE register has a tuning range of
±12.5%.
When the OSCTUNE register is modified, the INTOSC
and INTRC frequencies will begin shifting to the new fre-
quency. The INTRC clock will reach the new frequency
within 8 clock cycles (approximately 8 * 32 s = 256 s);
the INTOSC clock will stabilize within 1 ms. Code execu-
tion continues during this shift. There is no indication that
the shift has occurred. Operation of features that depend
on the 31.25 kHz INTRC clock source frequency, such
as the WDT, Fail-Safe Clock Monitor and peripherals,
will also be affected by the change in frequency.
R/W-0
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
TUN3
OSCTUNE REGISTER
R/W-0
TUN2
 2005 Microchip Technology Inc.
x = Bit is unknown
R/W-0
TUN1
R/W-0
TUN0
bit 0