PIC16F631_08 Datasheet, PDF (28/306 Pages) Microchip Technology – 20-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F631/677/685/687/689/690
2.2 Data Memory Organization
The data memory (see Figures 2-6 through 2-8) is
partitioned into four banks which contain the General
Purpose Registers (GPR) and the Special Function
Registers (SFR). The Special Function Registers are
located in the first 32 locations of each bank. The
General Purpose Registers, implemented as static
RAM, are located in the last 96 locations of each Bank.
Register locations F0h-FFh in Bank 1, 170h-17Fh in
Bank 2 and 1F0h-1FFh in Bank 3 point to addresses
70h-7Fh in Bank 0. The actual number of General
Purpose Resisters (GPR) in each Bank depends on the
device. Details are shown in Figures 2-4 through 2-8.
All other RAM is unimplemented and returns ‘0’ when
read. RP<1:0> of the STATUS register are the bank
select bits:
RP1 RP0
0
0 → Bank 0 is selected
0
1 → Bank 1 is selected
1
0 → Bank 2 is selected
1
1 → Bank 3 is selected
2.2.1
GENERAL PURPOSE REGISTER
FILE
The register file is organized as 128 x 8 in the
PIC16F687 and 256 x 8 in the
PIC16F685/PIC16F689/PIC16F690. Each register is
accessed, either directly or indirectly, through the File
Select Register (FSR) (see Section 2.4 “Indirect
Addressing, INDF and FSR Registers”).
2.2.2 SPECIAL FUNCTION REGISTERS
The Special Function Registers are registers used by
the CPU and peripheral functions for controlling the
desired operation of the device (see Tables 2-1
through 2-4). These registers are static RAM.
The special registers can be classified into two sets:
core and peripheral. The Special Function Registers
associated with the “core” are described in this section.
Registers related to the operation of peripheral features
are described in the section of that peripheral feature.
DS41262E-page 26
© 2008 Microchip Technology Inc.