Datasheet

ST72321Rx ST72321ARx ST72321Jx
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3 REGISTER & MEMORY MAP
As shown in Figure 4, the MCU is capable of ad-
dressing 64K bytes of memories and I/O registers.
The available memory locations consist of 128
bytes of register locations, up to 2Kbytes of RAM
and up to 60Kbytes 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-
seved area can have unpredictable effects on the
device.
Related Documentation
AN 985: Executing Code in ST7 RAM
Figure 4. Memory Map
0000h
RAM
Program Memory
(60K, 48K or 32K)
Interrupt & Reset Vectors
HW Registers
0080h
007Fh
0FFFh
(see Table 3)
1000h
FFDFh
FFE0h
FFFFh
(see Table 8)
0880h
Reserved
087Fh
Short Addressing
RAM (zero page)
256 Bytes Stack
16-bit Addressing
RAM
0100h
01FFh
0080h
0200h
00FFh
or 087Fh
32 KBytes
8000h
60 KBytes
48 KBytes
FFFFh
1000h
4000h
(2048, 1536 or 1024 Bytes)
or 067Fh
or 047Fh