STMicroelectronics PSD833F2-90M

Overview

PSD833F2-90M from STMicroelectronics is a Flash in-system programmable (ISP) peripheral IC for 8-bit microcontrollers, integrating dual-bank Flash (1 Mbit primary + 256 Kbit secondary), 256 Kbit SRAM, 27 reconfigurable I/O ports, and a hybrid PLD (3000-gate CPLD + user-defined DPLD). It supports concurrent read/erase/write operations and operates at 5 V with 90 ns access time. Used in legacy industrial MCU systems requiring field-upgradable firmware and flexible address decoding.

For engineers reviewing the PSD833F2-90M datasheet, PSD833F2-90M pinout, PSD833F2-90M application, or PSD833F2-90M equivalent, key selection criteria include ISP JTAG support, dual-bank Flash concurrency, PLD-based chip select decoding, and compatibility with 80C51/68HC11 bus protocols.

Technical Context

The PSD833F2-90M implements a tightly coupled memory-peripheral architecture where the primary Flash (32K × 8, 8 uniform sectors) and secondary Flash (64K × 4, 4 uniform sectors) operate independently under JTAG-controlled ISP. Its page register expands MCU address space by 256×, enabling access to >16 MB of logical memory using an 8-bit bus.

The integrated PLD comprises two distinct blocks: a 16-output macrocell CPLD for glue logic and timing-critical control signals, and a decode PLD (DPLD) that performs user-configurable internal chip select generation-eliminating external logic for memory mapping in 8-bit embedded systems.

Key Specifications

Pinout & Package

PQFP52 (M) package - 52-pin plastic quad flat pack with 0.65 mm pitch, ECOPACK® compliant, suitable for surface-mount assembly in industrial control modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Flash+PLD peripheral applications.

Compared with PSD833F2-90M, PSD834F2-90M offers double primary Flash capacity with identical timing and PLD capability, while PSD853F2-90M adds EEPROM and security extensions-making each optimal for distinct firmware scalability or data retention requirements.

Availability

PSD833F2-90M is available at Aetrix Electronics and suitable for industrial PLC I/O modules, legacy medical device controllers, and automotive body control units requiring stable component supply and long-term obsolescence management.

Supply support for PSD833F2-90M includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, and memory solutions for industrial, automotive, and consumer markets.

The PSD8XXFX product line was engineered specifically to extend the life and capability of 8-bit MCU platforms by integrating Flash, SRAM, and programmable logic into a single ISP-capable peripheral - targeting cost-sensitive, long-lifecycle embedded systems.

FAQ

Is PSD833F2-90M still in production?

No - PSD833F2-90M is marked obsolete by STMicroelectronics (Doc ID 7833 Rev 7, Table 1). However, Aetrix Electronics maintains verified legacy inventory with full traceability, extended warranty, and engineering support for ongoing production and repair programs.

What MCU families does PSD833F2-90M directly interface with?

It natively supports 80C51XA, 80C251, 80C31, and 68HC11 derivatives via documented bus timing and control signal mappings (Sections 15.5–15.8, Doc ID 7833). No external bus translators are required for these architectures.

Can the PLD logic be reconfigured in-system after initial programming?

Yes - both the CPLD and DPLD blocks are fully reprogrammable via JTAG. The OMC and IMC configurations, including product term allocations and output enables, are stored in Flash and can be updated without power cycle or device removal.

Does PSD833F2-90M support 3 V operation?

No - PSD833F2-90M is a 5 V-only device (see Table 40, Operating Conditions). It is not compatible with 3 V logic families or mixed-voltage systems without level-shifting circuitry on all I/O and control lines.