16F84 MICROCHIP [Microchip Technology], 16F84 Datasheet - Page 11

• Manufacturer Part Number: 16F84
• Description: 18-pin Flash/EEPROM 8-Bit Microcontrollers
• Manufacturer: MICROCHIP [Microchip Technology]

4.0
There are two memory blocks in the PIC16F8X. These
are the program memory and the data memory. Each
block has its own bus, so that access to each block can
occur during the same oscillator cycle.
The data memory can further be broken down into the
general purpose RAM and the Special Function
Registers (SFRs). The operation of the SFRs that
control the “core” are described here. The SFRs used
to control the peripheral modules are described in the
section discussing each individual peripheral module.
The data memory area also contains the data
EEPROM memory. This memory is not directly mapped
into the data memory, but is indirectly mapped. That is,
an indirect address pointer specifies the address of the
data EEPROM memory to read/write. The 64 bytes of
data EEPROM memory have the address range
0h-3Fh. More details on the EEPROM memory can be
found in Section 7.0.
4.1
The PIC16FXX has a 13-bit program counter capable
of addressing an 8K x 14 program memory space. For
the PIC16F83 and PIC16CR83, the first 512 x 14
(0000h-01FFh)
(Figure 4-1). For the PIC16F84 and PIC16CR84, the
first 1K x 14 (0000h-03FFh) are physically imple-
mented (Figure 4-2). Accessing a location above the
physically implemented address will cause a wrap-
around. For example, for the PIC16F84 locations 20h,
420h, 820h, C20h, 1020h, 1420h, 1820h, and 1C20h
will be the same instruction.
The reset vector is at 0000h and the interrupt vector is
at 0004h.
1998 Microchip Technology Inc.
MEMORY ORGANIZATION
Program Memory Organization
are
physically
implemented
FIGURE 4-1:
FIGURE 4-2:
CALL, RETURN
RETFIE, RETLW
CALL, RETURN
RETFIE, RETLW
Peripheral Interrupt Vector
Peripheral Interrupt Vector
PROGRAM MEMORY MAP
AND STACK -
PIC16F83/CR83
PROGRAM MEMORY MAP
AND STACK -
PIC16F84/CR84
Stack Level 1
Stack Level 8
Stack Level 1
Stack Level 8
Reset Vector
Reset Vector
PC<12:0>
PC<12:0>
PIC16F8X
13
13
DS30430C-page 11
1FFFh
1FFFh
0000h
0004h
1FFh
0000h
0004h
3FFh