Datasheet

 2012 Microchip Technology Inc. DS30575A-page 123
PIC18F97J94 FAMILY
6.3.4 SPECIAL FUNCTION REGISTERS
The Special Function Registers (SFRs) are registers
used by the CPU and peripheral modules for controlling
the desired operation of the device. These registers are
implemented as static RAM. SFRs start at the top of
data memory (FFFh) and extend downward to occupy
all of Bank 15 (F00h to FFFh), Bank 14 (E00h to EFFh)
and part of Bank 13 (DFAh to DFFh).
A list of these registers is given in Table 6-2.
The SFRs can be classified into two sets: those
associated with the “core” device functionality (ALU,
Resets and interrupts) and those related to the
peripheral functions. The Reset and Interrupt registers
are described in their respective chapters, while the
ALU’s STATUS register is described later in this section.
Registers related to the operation of the peripheral
features are described in the chapter for that peripheral.
The SFRs are typically distributed among the
peripherals whose functions they control. Unused SFR
locations are unimplemented and read as ‘0’s.