PIC16LF1503 Datasheet, PDF (17/340 Pages) Microchip Technology – 14-Pin Flash, 8-Bit Microcontrollers

3.1.1.2 Indirect Read with FSR
The program memory can be accessed as data by set-
ting bit 7 of the FSRxH register and reading the match-
ing INDFx register. The MOVIW instruction will place the
lower 8 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 pro-
gram memory via the FSR require one extra instruction
cycle to complete. Example 3-2 demonstrates access-
ing 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
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
3.2 Data Memory Organization
The data memory is partitioned in 32 memory banks
with 128 bytes in a bank. Each bank consists of
(Figure 3-2):
• 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 Section 3.5 “Indirect
Addressing” for more information.
Data Memory uses a 12-bit address. The upper 7-bit of
the address define the Bank address and the lower
5-bits select the registers/RAM in that bank.
PIC16(L)F1503
3.2.1 CORE REGISTERS
The core registers contain the registers that directly
affect the basic operation. The core registers occupy
the first 12 addresses of every data memory bank
(addresses x00h/x08h through x0Bh/x8Bh). These
registers are listed below in Table 3-2. For for detailed
information, see Table 3-4.
TABLE 3-2: CORE REGISTERS
Addresses
x00h or x80h
x01h or x81h
x02h or x82h
x03h or x83h
x04h or x84h
x05h or x85h
x06h or x86h
x07h or x87h
x08h or x88h
x09h or x89h
x0Ah or x8Ah
x0Bh or x8Bh
BANKx
INDF0
INDF1
PCL
STATUS
FSR0L
FSR0H
FSR1L
FSR1H
BSR
WREG
PCLATH
INTCON
 2011 Microchip Technology Inc.
Preliminary
DS41607A-page 17