PIC16C505
4.2
Data Memory Organization
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 PIC16C505, the register file is composed of 8
special function registers, 24 general purpose
registers, and 48 general purpose registers that may
be addressed using a banking scheme (Figure 4-2).
4.2.1
GENERAL PURPOSE REGISTER FILE
The general purpose register file is accessed either
directly or indirectly through the file select register
FSR (Section 4.8).
FIGURE 4-2:
PIC16C505 REGISTER FILE MAP
FSR<6:5>
File Address
00h
01h
02h
03h
04h
05h
06h
07h
08h
0Fh
10h
General
Purpose
Registers
1Fh
Bank 0
Note 1:
Not a physical register.
00
INDF
(1)
TMR0
PCL
STATUS
FSR
OSCCAL
PORTB
PORTC
General
Purpose
Registers
20h
01
40h
10
60h
11
Addresses map back to
addresses in Bank 0.
2Fh
30h
General
Purpose
Registers
3Fh
Bank 1
4Fh
50h
General
Purpose
Registers
5Fh
Bank 2
6Fh
70h
General
Purpose
Registers
7Fh
Bank 3
DS40192A-page 12
Preliminary
©
1998 Microchip Technology Inc.
MICROCHIP [ MICROCHIP TECHNOLOGY ]
