Datasheet

ST72334J/N, ST72314J/N, ST72124J
13/153
4 REGISTER & MEMORY MAP
As shown in the Figure 5, the MCU is capable of
addressing 64K bytes of memories and I/O regis-
ters.
The available memory locations consist of 128
bytes of register locations, 384 or 512 bytes of
RAM, up to 256 bytes of data EEPROM and 4 or
8 Kbytes of user program memory. The RAM
space includes up to 256 bytes for the stack from
0100h to 01FFh.
The highest address bytes contain the user reset
and interrupt vectors.
IMPORTANT: Memory locations marked as “Re-
served” must never be accessed. Accessing a re-
served area can have unpredictable effects on the
device.
Figure 5. Memory Map
0000h
Interrupt & Reset Vectors
HW Registers
027Fh
0080h
16-bit Addressing
RAM
007Fh
0200h / 0280h
0BFFh
Reserved
0080h
(see Table 2)
0C00h
FFDFh
FFE0h
FFFFh
(see Table 5 on page 34)
027Fh
C000h
Reserved
256 Bytes Data EEPROM
0CFFh
0D00h
BFFFh
00FFh
0100h
01FFh
0200h
8K Bytes
E000h
16K Bytes
Program
Short Addressing RAM
Zero page
0080h
00FFh
01FFh
01FFh
384 Bytes RAM
512 Bytes RAM
Stack or
16-bit Addressing RAM
0100h
Memory
Program
Memory
8 KBytes
E000h
C000h
16 KBytes
FFFFh
(128 Bytes)
(256 Bytes)
Short Addressing RAM
Zero page
Stack or
16-bit Addressing RAM
(128 Bytes)
(256 Bytes)