PSD934210MT View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

PSD934210MT

Flash PSD, 3.3V Supply, for 8-bit MCUs 2 Mbit + 256 Kbit Dual Flash Memories and 64 Kbit SRAM

STMicroelectronics 

PSD834F2V

Configuration Modes for MCUs with Separate

Program and Data Spaces. Separate Space

Modes. Program space is separated from Data

space. For example, Program Select Enable

(PSEN, CNTL2) is used to access the program

code from the primary Flash memory, while Read

Strobe (RD, CNTL1) is used to access data from

the secondary Flash memory, SRAM and I/O Port

blocks. This configuration requires the VM register

to be set to 0Ch (see Figure 7).

Figure 7. 8031 Memory Modules – Separate Space

DPLD

RS0

CSBOOT0-3

FS0-FS7

Primary

Flash

Memory

CS

OE

Secondary

Flash

Memory

CS

OE

SRAM

CS

OE

PSEN

RD

Combined Space Modes. The Program and

Data spaces are combined into one memory

space that allows the primary Flash memory, sec-

ondary Flash memory, and SRAM to be accessed

by either Program Select Enable (PSEN, CNTL2)

AI02869C

or Read Strobe (RD, CNTL1). For example, to

configure the primary Flash memory in Combined

space, bits b2 and b4 of the VM register are set to

1 (see Figure 8).

Figure 8. 8031 Memory Modules – Combined Space

RD

VM REG BIT 3

VM REG BIT 4

PSEN

VM REG BIT 1

VM REG BIT 2

VM REG BIT 0

DPLD

RS0

CSBOOT0-3

FS0-FS7

Primary

Flash

Memory

CS

OE

Secondary

Flash

Memory

CS

OE

SRAM

CS

OE

RD

AI02870C

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