PIC12F629-I/SN Microchip Technology Inc., PIC12F629-I/SN Datasheet - Page 20

• Manufacturer Part Number: PIC12F629-I/SN
• Description: 8 PIN, 1.75 KB FLASH, 64 RAM, 6 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC12F629-I/SN

• Comparators: 1
• Cpu Speed: 5 MIPS
• Eeprom Memory: 128 Bytes
• Input Output: 5
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 8-pin SOIC-N
• Programmable Memory: 1.75K Bytes
• Ram Size: 64 Bytes
• Speed: 20 MHz
• Timers: 1-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC12F629/675
2.4
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 actu-
ally 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 (STATUS<7>), as
shown in Figure 2-4.
FIGURE 2-4:
DS41190C-page 18
Bank Select Location Select
RP1
For memory map detail see Figure 2-2.
Note 1: The RP1 and IRP bits are reserved; always maintain these bits clear.
(1)
Indirect Addressing, INDF and
FSR Registers
RP0
Direct Addressing
6
Data
Memory
DIRECT/INDIRECT ADDRESSING PIC12F629/675
From Opcode
7Fh
00h
Bank 0
00
0
Bank 1
01
Bank 2
10
Not Used
A simple program to clear RAM location 20h-2Fh using
indirect addressing is shown in Example 2-1.
EXAMPLE 2-1:
NEXT
CONTINUE
Bank 3
11
IRP
movlw
movwf
clrf
incf
btfss
goto
Bank Select
180h
(1)
1FFh
0x20
FSR
INDF
FSR
FSR,4
NEXT
7
Indirect Addressing
INDIRECT ADDRESSING
 2003 Microchip Technology Inc.
;initialize pointer
;to RAM
;clear INDF register
;inc pointer
;all done?
;no clear next
;yes continue
FSR Register
Location Select
0