M37544 Datasheet, PDF (13/68 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

7544 Group
Memory
Special function register (SFR) area
The SFR area in the zero page contains control registers such as
I/O ports and timers.
RAM
RAM is used for data storage and for a stack area of subroutine
calls and interrupts.
ROM
The first 128 bytes and the last 2 bytes of ROM are reserved for
device testing and the rest is a user area for storing programs.
Interrupt vector area
The interrupt vector area contains reset and interrupt vectors.
Zero page
The 256 bytes from addresses 000016 to 00FF16 are called the
zero page area. The internal RAM and the special function regis-
ters (SFR) are allocated to this area.
The zero page addressing mode can be used to specify memory
and register addresses in the zero page area. Access to this area
with only 2 bytes is possible in the zero page addressing mode.
Special page
The 256 bytes from addresses FF0016 to FFFF16 are called the
special page area. The special page addressing mode can be
used to specify memory addresses in the special page area. Ac-
cess to this area with only 2 bytes is possible in the special page
addressing mode.
■ Note on use
The content of RAM is undefined when the microcomputer is re-
set. The initial values must be surely set before you use it.
RAM area
RAM capacity
(bytes)
256
address
XXXX16
013F16
ROM area
ROM capacity
(bytes)
8192
address
YYYY16
E00016
address
ZZZZ16
E08016
Fig. 13 Memory map diagram
RAM
000016
004016
010016
SFR area
Zero page
XXXX16
Reserved area
044016
Disable
YYYY16
Reserved ROM area
(128 bytes)
ZZZZ16
ROM
FF0016
FFDC16
Interrupt vector area
FFFE16
FFFF16 ^{Reserved ROM area}
Special page
Rev.1.04 2004.06.08 page 13 of 66
REJ03B0012-0104Z