STMicroelectronics PSD833F2-90MI

Overview

PSD833F2-90MI 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 + DPLD) with 16 output macrocells and 24 input macrocells. It operates at 5 V and supports concurrent read/erase/write across memory banks, enabling real-time firmware updates in embedded control systems.

For engineers reviewing the PSD833F2-90MI datasheet, PSD833F2-90MI pinout, PSD833F2-90MI application, or PSD833F2-90MI equivalent, key selection criteria include ISP via JTAG, page register–enabled 256× address space expansion, Turbo Bit–accelerated PLD timing, configurable open-drain I/O (16 pins), and ECOPACK®-compliant PQFP52 packaging for legacy 8-bit MCU co-processing.

Technical Context

The PSD833F2-90MI implements a tightly coupled architecture where the PLD subsystem (CPLD + DPLD) performs dynamic chip select decoding and glue logic offload, while the dual-bank Flash enables non-blocking firmware patching-read from Bank A while erasing/writing Bank B. Its MCU bus interface supports multiplexed and non-multiplexed 8-bit buses (e.g., 80C51XA, 68HC11).

Memory access is managed through dedicated sector protection registers, Ready/Busy (PC3) signaling, and Data Polling (DQ7)/Toggle (DQ6) status flags. The integrated page register extends the microcontroller's 16-bit address space to 24-bit logical addressing, and the JTAG port provides full-chip ISP without requiring external programming hardware beyond a low-cost FlashLINK cable.

Key Specifications

Pinout & Package

PSD833F2-90MI is housed in a 52-pin Plastic Quad Flat Package (PQFP52), RoHS-compliant and ECOPACK® certified. Pin assignments follow STMicroelectronics' standard layout for this family, with dedicated JTAG (TCK/TMS/TDI/TDO), MCU bus interface (AD0–AD7, A8–A15, RD#, WR#, CS#), PLD I/O, and power/ground distribution.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Flash-based programmable peripheral applications.

Compared with PSD833F2-90MI, PSD834F2-90MI offers scalable Flash capacity without altering PLD logic or power profile, while PSD853F2-90MI trades package form factor for identical functionality-making the former a true functional upgrade and the latter a mechanical alternative.

Availability

PSD833F2-90MI is available at Aetrix Electronics and suitable for industrial PLC upgrades, legacy automotive ECU retrofits, and medical device firmware expansion requiring stable component supply and long-lifecycle support.

Supply support for PSD833F2-90MI 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, analog ICs, power management, and memory solutions for industrial, automotive, and consumer markets.

The PSD8XXFX product line was engineered specifically to extend the capabilities of legacy 8-bit MCUs-providing integrated Flash, SRAM, and programmable logic in a single chip to eliminate discrete glue logic and reduce system complexity in cost-sensitive embedded designs.

FAQ

Is PSD833F2-90MI still in production?

No-PSD833F2-90MI is marked as Obsolete by STMicroelectronics (as confirmed in Doc ID 7833 Rev 7, Table 1). However, Aetrix Electronics maintains verified, traceable inventory sourced from authorized legacy channels, with full lot traceability and extended lifecycle support documentation for ongoing production programs.

What MCU families does PSD833F2-90MI directly support?

PSD833F2-90MI natively interfaces with 80C31, 80C251, 80C51XA, and 68HC11 MCUs, as detailed in Sections 15.5–15.8 of the datasheet. Its bus timing, control signal polarity, and address/data multiplexing modes are pre-validated for these architectures-no FPGA or custom adapter required.

Can the PLD logic be reprogrammed in the field?

Yes-the CPLD and DPLD blocks are fully in-system programmable via JTAG. Configuration bitstreams are stored in Flash and loaded automatically at power-up; users can update PLD logic independently of MCU firmware using ST's PSDSoft development tools and FlashLINK hardware.

Does PSD833F2-90MI support 3.3 V operation?

No-PSD833F2-90MI is a 5 V-only device (VCC = 4.5–5.5 V), specified in Table 40 of the datasheet. It lacks 3 V I/O tolerance or internal voltage regulation; interfacing with 3.3 V MCUs requires level-shifting on all shared bus signals (AD0–AD7, A8–A15, control lines).