PIC16F877-20/P Microchip Technology, PIC16F877-20/P Datasheet - Page 29

• Manufacturer Part Number: PIC16F877-20/P
• Description: IC MCU FLASH 8KX14 EE 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877-20/P

• Core Size: 8-Bit
• Program Memory Size: 14KB (8K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• 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: 0°C ~ 70°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Controller Family/series: PIC16F
• No. Of I/o's: 33
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 368Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 444-1001 - DEMO BOARD FOR PICMICRO MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

2.5
The INDF register is not a physical register. Addressing
the INDF register will cause indirect addressing.
Indirect addressing is possible by using the INDF reg-
ister. Any instruction using the INDF register actually
accesses the register pointed to by the File Select Reg-
ister, FSR. Reading the INDF register itself, indirectly
(FSR = ’0’) will read 00h. Writing to the INDF register
indirectly results in a no operation (although status bits
may be affected). An effective 9-bit address is obtained
by concatenating the 8-bit FSR register and the IRP bit
(STATUS<7>), as shown in Figure 2-6.
FIGURE 2-6:
Bank Select
2001 Microchip Technology Inc.
RP1:RP0
Note 1: For register file map detail, see Figure 2-3.
Indirect Addressing, INDF and
FSR Registers
Location Select
6
Direct Addressing
Data
Memory
DIRECT/INDIRECT ADDRESSING
From Opcode
(1)
00h
7Fh
Bank 0
00
0
80h
FFh
Bank 1
01
100h
17Fh
Bank 2
10
A simple program to clear RAM locations 20h-2Fh
using indirect addressing is shown in Example 2-2.
EXAMPLE 2-2:
NEXT
CONTINUE
180h
1FFh
Bank 3
11
MOVLW 0x20
MOVWF FSR
CLRF
INCF
BTFSS FSR,4
GOTO
:
IRP
Bank Select
INDF
FSR,F
NEXT
7
INDIRECT ADDRESSING
Indirect Addressing
PIC16F87X
;initialize pointer
;to RAM
;clear INDF register
;inc pointer
;all done?
;no clear next
;yes continue
FSR register
DS30292C-page 27
Location Select
0