PIC16F874-04I/PQ Microchip Technology, PIC16F874-04I/PQ Datasheet - Page 110

• 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

PICmicro MID-RANGE MCU FAMILY
6.5
DS31006A-page 6-16
Design Tips
Question 1:
Answer 1:
When a device with more then 2K words of program memory is used, the calling of subroutines
may require that the PCLATH register be loaded prior to the CALL (or GOTO) instruction to specify
the correct program memory page that the routine is located on. The following instructions will
correctly load PCLATH register, regardless of the program memory location of the label SUB_1.
SUB_1
Question 2:
Answer 2:
Example 6-4
of the code may be removed.
MOVLW
MOVWF
CALL
:
:
:
:
RETURN
shows this. If the device you are using does not use all 4 data memory banks, some
Program execution seems to get lost.
I need to initialize RAM to ’0’s. What is an easy way to do that?
HIGH (SUB_1)
PCLATH
SUB_1
; Select Program Memory Page of
;
; Call the desired routine
; Start of routine
; Return from routine
Routine.
1997 Microchip Technology Inc.