
2009 Microchip Technology Inc.
DS41399A-page 9
MCV18E
2.0
MEMORY ORGANIZATION
There are two memory blocks in the MCV18E device.
Each block (program memory and data memory) has
its own bus so that concurrent access can occur.
2.1
Program Memory Organization
The MCV18E has a 13-bit Program Counter (PC) capa-
ble of addressing an 8K x 14 program memory space.
The MCV18E has 2K x 14 words of program memory.
Accessing a location above the physically implemented
address will cause a wrap-around.
The Reset vector is at 0000h and the interrupt vector is
at 0004h.
FIGURE 2-1:
PROGRAM MEMORY MAP
AND STACK OF MCV18E
2.2
Data Memory Organization
The data memory is partitioned into multiple banks
which contain the General Purpose Registers (GPR)
and the Special Function Registers (SFR). Bits RP1
and RP0 of the STATUS register are the bank select
bits.
Each bank extends up to 7Fh (128 bytes). The lower
locations of each bank are reserved for the Special
Function Registers. Above the Special Function
Registers
are
General
Purpose
Registers,
implemented as static RAM. All implemented banks
contain Special Function Registers. The upper 16 bytes
of GPR space and some “high use” Special Function
Registers in Bank 0 are mirrored in Bank 1 for code
reduction and quicker access.
PC<12:0>
13
0000h
0004h
0005h
07FFh
0800h
1FFFh
Stack Level 1
Stack Level 8
Reset Vector
Interrupt Vector
On-chip Program
Memory
CALL, RETURN
RETFIE, RETLW
U
s
e
rMe
mo
ry
Sp
a
c
e
RP<1:0>(1)
(Status<6:5>)
Bank
00
0
01
1
10
2(2)
11
3(2)
Note 1:
Maintain Status bit 6 clear to ensure
upward compatibility with future products.
2:
Not implemented