P12C508 Microchip Technology, P12C508 Datasheet - Page 12

• Manufacturer Part Number: P12C508
• Description: 8-Pin / 8-Bit CMOS Microcontroller
• Manufacturer: Microchip Technology

PIC12C5XX
4.2
Data memory is composed of registers, or bytes of
RAM. Therefore, data memory for a device is specified
by its register file. The register file is divided into two
functional groups: special function registers and
general purpose registers.
The special function registers include the TMR0
register, the Program Counter (PC), the Status
Register, the I/O registers (ports), and the File Select
Register (FSR). In addition, special purpose registers
are used to control the I/O port configuration and
prescaler options.
The general purpose registers are used for data and
control information under command of the instructions.
For the PIC12C508, the register file is composed of 7
special function registers and 25 general purpose
registers (Figure 4-2).
For the PIC12C509, the register file is composed of 7
special function registers, 25 general purpose
registers, and 16 general purpose registers that may
be addressed using a banking scheme (Figure 4-3).
4.2.1
The general purpose register file is accessed either
directly or indirectly through the file select register
FSR (Section 4.7).
FIGURE 4-3:
DS40139A-page 12
Data Memory Organization
GENERAL PURPOSE REGISTER FILE
PIC12C509 REGISTER FILE MAP
File Address
FSR<6:5>
Note 1:
0Fh
00h
01h
02h
03h
04h
05h
06h
07h
Advance Information
1Fh
10h
Not a physical register. See Section 4.7
General
Purpose
Registers
OSCCAL
General
Purpose
Registers
STATUS
INDF
Bank 0
TMR0
GPIO
PCL
FSR
00
(1)
3Fh
30h
2Fh
20h
Addresses map
back to
addresses
in Bank 0.
FIGURE 4-2:
General
Purpose
Registers
Bank 1
01
Note 1:
File Address
00h
01h
02h
03h
04h
05h
06h
07h
1Fh
Not a physical register. See Section 4.7
PIC12C508 REGISTER FILE
MAP
Registers
1996 Microchip Technology Inc.
OSCCAL
Purpose
General
STATUS
INDF
TMR0
GPIO
PCL
FSR
(1)