
2011-2012 Microchip Technology Inc.
Preliminary
DS41575B-page 19
PIC16(L)F1933
3.1.1.2
Indirect Read with FSR
The program memory can be accessed as data by
setting bit 7 of the FSRxH register and reading the
matching INDFx register. The MOVIW instruction will
place the lower eight bits of the addressed word in the
W register. Writes to the program memory cannot be
performed via the INDF registers. Instructions that
access the program memory via the FSR require one
demonstrates accessing the program memory via an
FSR.
The HIGH directive will set bit<7> if a label points to a
location in program memory.
EXAMPLE 3-2:
ACCESSING PROGRAM
MEMORY VIA FSR
3.2
Data Memory Organization
The data memory is partitioned in 32 memory banks
with 128 bytes in a bank. Each bank consists of
12 core registers
20 Special Function Registers (SFR)
Up to 80 bytes of General Purpose RAM (GPR)
16 bytes of common RAM
The active bank is selected by writing the bank number
into the Bank Select Register (BSR). Unimplemented
memory will read as ‘0’. All data memory can be
accessed either directly (via instructions that use the
file registers) or indirectly via the two File Select
Registers
(FSR).
See
3.2.1
CORE REGISTERS
The core registers contain the registers that directly
affect the basic operation of the PIC16(L)F1933. These
registers are listed below:
INDF0
INDF1
PCL
STATUS
FSR0 Low
FSR0 High
FSR1 Low
FSR1 High
BSR
WREG
PCLATH
INTCON
constants
RETLW DATA0
;Index0 data
RETLW DATA1
;Index1 data
RETLW DATA2
RETLW DATA3
my_function
;… LOTS OF CODE…
MOVLW
LOW constants
MOVWF
FSR1L
MOVLW
HIGH constants
MOVWF
FSR1H
MOVIW
0[FSR1]
;THE PROGRAM MEMORY IS IN W
Note:
The core registers are the first 12
addresses of every data memory bank.