PIC16F877T-20I/L Microchip Technology, PIC16F877T-20I/L Datasheet - Page 44

• Manufacturer Part Number: PIC16F877T-20I/L
• Description: IC MCU FLASH 8KX14 EE 44PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877T-20I/L

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-PLCC
• For Use With: DVA16XL441 - ADAPTER DEVICE ICE 44PLCC309-1040 - ADAPTER 44-PLCC ZIF TO 40-DIP309-1039 - ADAPTER 44-PLCC TO 40-DIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PICmicro MID-RANGE MCU FAMILY
DS31002A-page 2-14
Figure 2-7
and OSCCAL = 70h), and the changes achievable by the OSCCAL register.
Figure 2-7: Ideal Internal RC Oscillator Frequency vs. OSCCAL Register Value
Figure 2-8
frequency can corrected to 4 MHz. These bits can be considered the fine trimming of the
frequency. Sometimes the device frequency at the uncalibrated point cannot be corrected to 4
MHz by the fine trimming of the CAL3:CAL0 bits value. Therefore two additional bits are available
which give a large frequency offset (positive and negative) to move the frequency within the
range where the fine trimming can work. These bits are the CALSLW and CALFST bits, which
offset the internal RC frequency. The action of these bits are shown in
Figure
Figure 2-8: CAL3:CAL0 Trimming of Internal RC Oscillator Frequency Offset
Frequency
4 MHz
4 MHz
(@ 5V, 25˚C)
2-10.
(slowest frequency)
shows the possible device frequencies from the uncalibrated point (at V
shows an example of a device where by selecting one of the CAL3:CAL0 values, the
> 4 MHz
< 4 MHz
CAL3:CAL0 = 0h
CALFST = 0
CALSLW = 1
1.5%
CAL3:CAL0 = 0000
CAL3:CAL0 = 0h
CALFST = 0
CALSLW = 0
One of the 16 possible calibration points
CAL3:CAL0 = 07h
CALFST = 0
CALSLW = 0
CAL3:CAL0
Trim Window
CAL3:CAL0
Trim Window
CAL3:CAL0 = Fh
CALFST = 0
CALSLW = 0
1997 Microchip Technology Inc.
CAL3:CAL0 = 1111
(fastest frequency)
CAL3:CAL0 = Fh
CALFST = 1
CALSLW = x
See X-axis
Internal RC
Frequency at
device reset
CALFST = 0
CALFLW = 0
CAL3:CAL0 = 7h
Figure
DD
= 5V, 25 C,
2-9, and