PIC16F707 Datasheet, PDF (27/284 Pages) Microchip Technology – 40/44-Pin, Flash Microcontrollers with nanoWatt XLP and mTouch™ Technology

PIC16F707/PIC16LF707
2.5 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 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 of
the STATUS register, as shown in Figure 2-3.
A simple program to clear RAM location 020h-02Fh
using indirect addressing is shown in Example 2-2.
EXAMPLE 2-2: INDIRECT ADDRESSING
MOVLW
MOVWF
BANKISEL
NEXT CLRF
INCF
BTFSS
GOTO
CONTINUE
020h
FSR
020h
INDF
FSR
FSR,4
NEXT
;initialize pointer
;to RAM
;clear INDF register
;inc pointer
;all done?
;no clear next
;yes continue
FIGURE 2-3:
DIRECT/INDIRECT ADDRESSING
Direct Addressing
RP1 RP0 6
From Opcode 0
Indirect Addressing
IRP
7
File Select Register 0
Bank Select
Location Select
Bank Select
00
01
10
11
00h
180h
Location Select
Data
Memory
Note:
7Fh
Bank 0 Bank 1 Bank 2
For memory map detail, refer to Table 2-2.
Bank 3
1FFh
 2010 Microchip Technology Inc.
Preliminary
DS41418A-page 27