PIC12C508A-04I/P Microchip Technology, PIC12C508A-04I/P Datasheet - Page 20

• Manufacturer Part Number: PIC12C508A-04I/P
• Description: IC MCU OTP 512X12 8DIP
• Manufacturer: Microchip Technology
• Series: PIC® 12Cr

Specifications of PIC12C508A-04I/P

• Program Memory Type: OTP
• Program Memory Size: 768B (512 x 12)
• Package / Case: 8-DIP (0.300", 7.62mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Peripherals: POR, WDT
• Number Of I /o: 5
• Ram Size: 25 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC12C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 25 B
• Maximum Clock Frequency: 4 MHz
• Number Of Programmable I/os: 5
• Number Of Timers: 1
• Operating Supply Voltage: 2.5 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: DVMCPA, ICE2000
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: ISPICR1 - ADAPTER IN-CIRCUIT PROGRAMMINGDVMCPA - KIT DVR BOARD EVAL SYSTEM MXDEV1DVA12XP080 - ADAPTER DEVICE FOR MPLAB-ICEAC124001 - MODULE SKT PROMATEII 8DIP/SOIC
• Eeprom Size: -
• Data Converters: -
• Connectivity: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC12C5XX
4.8
The INDF register is not a physical register.
Addressing INDF actually addresses the register
whose address is contained in the FSR register (FSR
is a pointer ). This is indirect addressing.
EXAMPLE 4-1:
• Register file 07 contains the value 10h
• Register file 08 contains the value 0Ah
• Load the value 07 into the FSR register
• A read of the INDF register will return the value
• Increment the value of the FSR register by one
• A read of the INDR register now will return the
Reading INDF itself indirectly (FSR = 0) will produce
00h. Writing to the INDF register indirectly results in a
no-operation (although STATUS bits may be affected).
A simple program to clear RAM locations 10h-1Fh
using indirect addressing is shown in Example 4-2.
FIGURE 4-9:
DS40139E-page 20
of 10h
(FSR = 08)
value of 0Ah.
Indirect Data Addressing; INDF and
FSR Registers
bank select
DIRECT/INDIRECT ADDRESSING
(FSR)
6
INDIRECT ADDRESSING
Note 1: For register map detail see Section 4.2.
Note 2: PIC12C509, PIC12C509A, PIC12CR509A, PIC12CE519.
5
Direct Addressing
location select
Data
Memory
4
(opcode)
(1)
00h
0Fh
10h
0
1Fh
Bank 0
00
3Fh
Bank 1
Addresses
map back to
addresses
in Bank 0.
EXAMPLE 4-2:
NEXT
CONTINUE
The FSR is a 5-bit wide register. It is used in
conjunction with the INDF register to indirectly address
the data memory area.
The FSR<4:0> bits are used to select data memory
addresses 00h to 1Fh.
PIC12C508/PIC12C508A/PIC12CE518:
use banking. FSR<7:5> are unimplemented and read
as '1's.
PIC12C509/PIC12C509A/PIC12CR509A/
PIC12CE519: Uses FSR<5>. Selects between bank 0
and bank 1. FSR<7:6> is unimplemented, read as '1’ .
01
(2)
movlw
movwf
clrf
incf
btfsc
goto
:
HOW TO CLEAR RAM
USING INDIRECT
ADDRESSING
0x10
FSR
INDF
FSR,F
FSR,4
NEXT
6
Indirect Addressing
1999 Microchip Technology Inc.
bank
5
4
;initialize pointer
; to RAM
;clear INDF register
;inc pointer
;all done?
;NO, clear next
;YES, continue
location select
(FSR)
Does not
0