PIC16F628-20SLASHSS datasheet(26/160 Pages) MICROCHIP

26 / 160 page

PIC16F62X

DS40300B-page 26

Preliminary

4.4

Indirect Addressing, INDF and FSR

Registers

The INDF register is not a physical register. Addressing

the INDF register will cause indirect addressing.

Indirect addressing is possible by using the INDF register.

Any instruction using the INDF register actually accesses

data pointed to by the file select register (FSR). Reading

INDF itself indirectly will produce 00h. Writing to the INDF

tus 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 4-8.

A simple program to clear RAM location 20h-2Fh using

indirect addressing is shown in Example 4-1.

EXAMPLE 4-1:

INDIRECT ADDRESSING

movlw

0x20

;initialize pointer

movwf

FSR

;to RAM

clrf

INDF

;clear INDF register

incf

FSR

;inc pointer

btfss

FSR,4

;all done?

goto

;no clear next

;yes continue

CONTINUE:

FIGURE 4-8:

DIRECT/INDIRECT ADDRESSING PIC16F62X

For memory map detail see Figure 4-3.

Data

Memory

Indirect Addressing

Direct Addressing

bank select

location select

RP1

RP0

from opcode

IRP

FSR register

bank select

location select

180h

1FFh

00h

7Fh

Bank 0

Bank 1

Bank 2

Bank 3

PIC16F628-20/SS bảng dữ liệu(PDF) 26 Page - Microchip Technology

PIC16F628-20/SS bảng dữ liệu(HTML) 26 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

bảng dữ liệu tải về

Link URL