PIC16F874A-I/PT Microchip Technology, PIC16F874A-I/PT Datasheet - Page 40

• Manufacturer Part Number: PIC16F874A-I/PT
• Description: IC MCU FLASH 4K 20MHZ 44-TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F874A-I/PT

• Program Memory Type: FLASH
• Program Memory Size: 7KB (4K x 14)
• Package / Case: 44-TQFP, 44-VQFP
• 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
• 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
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 192 B
• Interface Type: I2C/SPI/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 3
• 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-ch x 10-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44PT3 - SOCKET TRAN ICE 44MQFP/TQFPAC164305 - MODULE SKT FOR PM3 44TQFP444-1001 - DEMO BOARD FOR PICMICRO MCUAC164020 - MODULE SKT PROMATEII 44TQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC16F87XA
An example of the complete four-word write sequence
is shown in Example 3-4. The initial address is loaded
into the EEADRH:EEADR register pair; the four words
of data are loaded using indirect addressing.
EXAMPLE 3-4:
DS39582B-page 38
; This write routine assumes the following:
;
; 1. A valid starting address (the least significant bits = ‘00’)is loaded in ADDRH:ADDRL
; 2. The 8 bytes of data are loaded, starting at the address in DATADDR
; 3. ADDRH, ADDRL and DATADDR are all located in shared data memory 0x70 - 0x7f
;
LOOP
BSF
BCF
MOVF
MOVWF
MOVF
MOVWF
MOVF
MOVWF
MOVF
MOVWF
INCF
MOVF
MOVWF
INCF
BSF
BSF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
NOP
NOP
BCF
BSF
BCF
INCF
MOVF
ANDLW
XORLW
BTFSC
GOTO
STATUS,RP1
STATUS,RP0
ADDRH,W
EEADRH
ADDRL,W
EEADR
DATAADDR,W
FSR
INDF,W
EEDATA
FSR,F
INDF,W
EEDATH
FSR,F
STATUS,RP0
EECON1,EEPGD
EECON1,WREN
INTCON,GIE
55h
EECON2
AAh
EECON2
EECON1,WR
EECON1,WREN
INTCON,GIE
STATUS,RP0
EEADR,F
EEADR,W
0x03
0x03
STATUS,Z
LOOP
WRITING TO FLASH PROGRAM MEMORY
;
; Bank 2
; Load initial address
;
;
;
; Load initial data address
;
; Load first data byte into lower
;
; Next byte
; Load second data byte into upper
;
;
; Bank 3
; Point to program memory
; Enable writes
; Disable interrupts (if using)
; Start of required write sequence:
; Write 55h
;
; Write AAh
; Set WR bit to begin write
; Any instructions here are ignored as processor
; halts to begin write sequence
; processor will stop here and wait for write complete
; after write processor continues with 3rd instruction
; Disable writes
; Enable interrupts (if using)
; Bank 2
; Increment address
; Check if lower two bits of address are ‘00’
; Indicates when four words have been programmed
;
; Exit if more than four words,
; Continue if less than four words
 2003 Microchip Technology Inc.