STMicroelectronics ST10R172LT1

Overview

ST10R172LT1 from STMicroelectronics is a 16-bit ROMless microcontroller featuring a 4-stage pipeline CPU, 1 KB on-chip RAM, and support for up to 16 MB linear address space. It integrates dual general-purpose timer units (GPT1/GPT2), a synchronous/asynchronous serial port (ASC0), high-speed synchronous serial port (XSSP), PWM unit, and 16-level priority interrupt system with 17 sources. Used in industrial motor control and embedded automation systems requiring deterministic real-time response.

For engineers reviewing the ST10R172LT1 datasheet, ST10R172LT1 pinout, ST10R172LT1 application, or ST10R172LT1 equivalent, key selection criteria include its 50 MHz max CPU frequency, 5V-tolerant I/Os (including fail-safe Port 5), external bus controller with five chip-selects, PLL-based clock generation, and PEC-accelerated data transfers.

Technical Context

The ST10R172LT1 implements a hybrid RISC/CISC architecture with register-based execution and multiple variable register banks accessed via a Context Pointer (CP). Its 4-stage pipeline enables single-cycle instruction execution at 50 MHz (40 ns cycle time), supported by dedicated multiply/divide hardware and barrel shifter.

Interrupt handling combines standard vectorized servicing with Peripheral Event Controller (PEC)–driven single-cycle memory-to-memory transfers across eight channels. The external bus controller supports configurable 8/16-bit demultiplexed or multiplexed addressing, programmable wait states via READY, and hold/arbitration protocols using HOLD/HLDA/BREQ signals.

Key Specifications

Pinout & Package

ST10R172LT1 is housed in a 100-pin Thin Quad Flat Pack (TQFP) package with 0.5 mm pitch, compliant with JEDEC MO-137AB. Pin assignments support multiplexed/demultiplexed external bus operation, dual timer I/O, ASC0 serial interface, XSSP, PWM output, and system control signals including RSTIN, RSTOUT, NMI, and CLKOUT.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit ROMless microcontroller applications.

Compared with ST10F269, ST10R172LT1 offers lower system cost via external memory but lacks flash persistence; versus XC164CS, it provides superior I/O flexibility and fail-safe inputs but no native CAN, making it more suitable for industrial motion control than vehicle networks.

Availability

ST10R172LT1 is available at Aetrix Electronics and suitable for industrial motor control, automated test equipment, power supply monitoring units, and programmable logic controller I/O modules requiring stable component supply throughout long-lifecycle production runs.

Supply support for ST10R172LT1 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, sensors, and automotive semiconductors.

The ST10 family was developed for high-performance embedded control applications demanding deterministic real-time response, flexible memory expansion, and robust industrial I/O - targeting motor drives, power conversion, and factory automation.

FAQ

What is the maximum operating frequency and corresponding instruction cycle time of the ST10R172LT1?

The ST10R172LT1 operates at up to 50 MHz CPU clock frequency, delivering a 40 ns instruction cycle time. This timing is achieved using the on-chip PLL or direct clock input, and is validated across the full industrial temperature range (–40°C to +125°C) per the datasheet's AC characteristics section.

Does the ST10R172LT1 include on-chip non-volatile program memory?

No, the ST10R172LT1 is a ROMless device. It contains 1 KB of on-chip dual-port RAM for data and stack usage but requires external program memory (e.g., EPROM, Flash, or SRAM) connected via its configurable external bus interface for code execution.

How does the Peripheral Event Controller (PEC) improve real-time performance?

The PEC performs single-cycle memory-to-memory data transfers without CPU involvement, reducing interrupt latency and freeing the core for computation. With eight independent channels and programmable transfer counters, it accelerates ADC sampling, DAC updates, and serial buffer management - critical for jitter-sensitive motor control loops.

What are the key electrical tolerances of the ST10R172LT1 I/O pins?

All I/O pins are 5V-tolerant. Port 5 (P5.10–P5.15) is fail-safe: inputs withstand –0.5 V to 5.5 V even when the device is unpowered. XTAL1/XTAL2 are 3V-tolerant (–0.5 V to VDD + 0.5 V). Power supply is strictly 3.3 V ±0.3 V; applying 5V to VDD will damage the device.