UPSD3253B-40 查看數據表（PDF） - STMicroelectronics

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UPSD3253B-40

Flash Programmable System Devices with 8032 Microcontroller Core and 256Kbit SRAM

STMicroelectronics 

µPSD325X DEVICES

ARCHITECTURE OVERVIEW

Memory Organization

The µPSD325X devices’ standard 8032 Core has

separate 64KB address spaces for Program mem-

ory 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 Sec-

ondary Flash (256Kbit). Except during flash mem-

ory programming or update, Flash memory can

only be read, not written to. A Page Register is

used to access memory beyond the 64K bytes ad-

dress space. Refer to the PSD Module for details

on mapping of the Flash memory.

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 µPSD325X devices: one 256 bytes

block is assigned for DDC data storage. Another

32K bytes resides in the PSD Module that can be

mapped to any address space defined by the user.

Figure 5. Memory Map and Address Space

MAIN

FLASH

EXT. RAM

SECONDARY

FLASH

32KB

128KB

OR

256KB

INT. RAM

FF

Indirect

Addressing

SFR

Direct

Addressing

7F

Indirect

or

Direct

Addressing

0

EXT. RAM

(DDC)

FFFF

256B

FF00

32KB

Flash Memory Space

Internal RAM Space

(256 Bytes)

External RAM Space

(MOVX)

AI07422

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).

Figure 6. 8032 MCU Registers

PCH

DPTR(DPH)

A

B

SP

PCL

PSW

R0-R7

DPTR(DPL)

Accumulator

B Register

Stack Pointer

Program Counter

Program Status Word

General Purpose

Register (Bank0-3)

Data Pointer Register

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