PIC12C671-04I/P Microchip Technology Inc., PIC12C671-04I/P Datasheet - Page 23

• Manufacturer Part Number: PIC12C671-04I/P
• Description: 8 PIN, 1.75 KB OTP, 128 RAM, 6 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC12C671-04I/P

• A/d Inputs: 4-Channel, 8-Bit
• Cpu Speed: 2.5 MIPS
• Eeprom Memory: 0 Bytes
• Input Output: 5
• Memory Type: OTP
• Number Of Bits: 8
• Package Type: 8-pin PDIP
• Programmable Memory: 1.75K Bytes
• Ram Size: 128 Bytes
• Speed: 4 MHz
• Timers: 1-8-bit
• Voltage, Range: 2.5-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

4.5
The INDF Register is not a physical register. Address-
ing the INDF Register will cause indirect addressing.
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 4-4. However, IRP is
not used in the PIC12C67X.
A simple program to clear RAM locations 20h-2Fh
using indirect addressing is shown in Example 4-1.
FIGURE 4-4:
1999 Microchip Technology Inc.
RP1 RP0
bank select
For register file map detail see Figure 4-2.
Note 1: The RP1 and IRP bits are reserved; always maintain these bits clear.
Indirect Addressing, INDF and FSR
Registers
(1)
location select
6
Direct Addressing
DIRECT/INDIRECT ADDRESSING
Data
Memory
from opcode
7Fh
00h
Bank 0
00
0
Bank 1
01
Bank 2
10
not used
EXAMPLE 4-1:
NEXT
CONTINUE
Bank 3
11
movlw
movwf
clrf
incf
btfss
goto
:
IRP
bank select
180h
1FFh
(1)
0x20
FSR
INDF
FSR,F
FSR,4
NEXT
INDIRECT ADDRESSING
7
Indirect Addressing
PIC12C67X
;initialize pointer
;to RAM
;clear INDF register
;inc pointer
;all done?
;no clear next
;yes continue
FSR register
DS30561B-page 23
location select
0