UPSD3234AV-24U1T STMicroelectronics, UPSD3234AV-24U1T Datasheet - Page 13

• Manufacturer Part Number: UPSD3234AV-24U1T
• Description: Flash Programmable System Devices with 8032 Microcontroller Core and 64Kbit SRAM
• Manufacturer: STMicroelectronics

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ARCHITECTURE OVERVIEW
Memory Organization
The uPSD323X Devices’s standard 8032 Core
has separate 64KB address spaces for Program
memory and Data Memory. Program memory is
where the 8032 executes instructions from. Data
memory is used to hold data variables. Flash
memory can be mapped in either program or data
space. The Flash memory consists of two flash
memory blocks: the main Flash (1 or 2Mbit) and
the Secondary Flash (256Kbit). Except during
flash memory programming or update, Flash
memory can only be read, not written to. A Page
Register is used to access memory beyond the
64K bytes address space. Refer to the PSD Mod-
ule for details on mapping of the Flash memory.
Figure 5. Memory Map and Address Space
Registers
The 8032 has several registers; these are the Pro-
gram Counter (PC), Accumulator (A), B Register
(B), the Stack Pointer (SP), the Program Status
Word (PSW), General purpose registers (R0 to
R7), and DPTR (Data Pointer register).
SECONDARY
FLASH
32KB
Flash Memory Space
MAIN
FLASH
128KB
256KB
OR
FF
7F
0
uPSD3234A, uPSD3234BV, uPSD3233B, uPSD3233BV
INT. RAM
Addressing
Addressing
Indirect
Indirect
Direct
Internal RAM Space
(256 Bytes)
or
SFR
Addressing
Direct
The 8032 core has two types of data memory (in-
ternal and external) that can be read and written.
The internal SRAM consists of 256 bytes, and in-
cludes the stack area.
The SFR (Special Function Registers) occupies
the upper 128 bytes of the internal SRAM, the reg-
isters can be accessed by Direct addressing only.
There are two separate blocks of external SRAM
inside the uPSD323X Devices: one 256 bytes
block is assigned for DDC data storage. Another
8K bytes resides in the PSD Module that can be
mapped to any address space defined by the user.
Figure 6. 8032 MCU Registers
DPTR(DPH)
PCH
FFFF
FF00
EXT. RAM
(DDC)
DPTR(DPL)
External RAM Space
(MOVX)
256B
R0-R7
PSW
PCL
SP
A
B
EXT. RAM
Accumulator
B Register
Stack Pointer
Program Counter
Program Status Word
General Purpose
Register (Bank0-3)
Data Pointer Register
8KB
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