PIC16F874-04I/PQ Microchip Technology, PIC16F874-04I/PQ Datasheet - Page 515

• Manufacturer Part Number: PIC16F874-04I/PQ
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,QFP,44PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F874-04I/PQ

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 192 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-MQFP, 44-PQFP
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 192 B
• Interface Type: MSSP, PSP, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 3 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
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163022, DV164120
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Section 28. ICSP
28.6
Other Benefits
ICSP provides other benefits, such as calibration and serialization. If program memory permits,
it would be cheaper and more reliable to store calibration constants in program memory instead
of using an external serial EEPROM. For example, if your system has a thermistor which can vary
from one system to another, storing some calibration information in a table format allows the
microcontroller to compensate (in software) for external component tolerances. System cost can
be reduced without affecting the required performance of the system by using software calibra-
tion techniques. But how does this relate to ICSP? The PICmicro has already been programmed
with firmware that performs a calibration cycle. The calibration data is transferred to a calibration
fixture. When all calibration data has been transferred, the fixture places the PICmicro in pro-
gramming mode and programs the PICmicro with the calibration data. Application note AN656,
In-Circuit Serial Programming of Calibration Parameters Using a PICmicro Microcontroller ,
shows exactly how to implement this type of calibration data programming.
The other benefit of ICSP is serialization. Each individual system can be programmed with a
unique or random serial number. One such application of a unique serial number would be for
security systems. A typical system might use DIP switches to set the serial number. Instead, this
number can be burned into program memory, thus reducing the overall system cost and lowering
the risk of tampering.
28
1997 Microchip Technology Inc.
DS31028A-page 28-7