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STMicroelectronics ST72F321R6T6TR
- Part No.:
- ST72F321R6T6TR
- Manufacturer:
- STMicroelectronics
- Category:
- Microcontrollers
- Package:
- 64-LQFP
- Datasheet:
-
ST72F321R6T6TR.pdf
- Description:
- IC MCU 8BIT 32KB FLASH 64LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,762
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Product details
Overview
ST72F321R6T6TR from STMicroelectronics is a 64-pin LQFP 8-bit microcontroller featuring 32KB Flash/ROM, 1KB RAM, 10-bit ADC with up to 16 channels, five timers (including PWM auto-reload and dual 16-bit), and three serial interfaces (SPI, SCI, I²C). It operates from 3.8–5.5V across –40°C to +85°C and targets industrial control panels requiring deterministic real-time response, low-power sensor node firmware, and embedded HMI subsystems.
For engineers reviewing the ST72F321R6T6TR datasheet, ST72F321R6T6TR pinout, ST72F321R6T6TR application, or ST72F321R6T6TR equivalent, this page delivers verified technical context, validated pin functions, confirmed peripheral timing behavior, and documented alternative selection guidance for legacy ST7 MCU migration paths.
Technical Context
This MCU implements an enhanced ST7 core with 63 basic instructions and 17 addressing modes, supporting in-application programming (IAP) and in-circuit programming (ICP) for Flash memory. Its clock system integrates a PLL for 2× frequency multiplication, internal RC oscillator, crystal/ceramic resonator support, and bypass mode for external clock injection.
Interrupt handling uses a nested controller with 14 vectors plus TRAP and RESET, and includes Top Level Interrupt (TLI) capability on 64-pin variants. Power management provides four low-power modes-Halt, Active-Halt, Wait, and Slow-with LVD and AVD supervision delivering interrupt-capable voltage monitoring at main and auxiliary rails.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | 8-bit ST7 CPU with 63 instructions and 17 addressing modes; enables compact firmware for resource-constrained industrial firmware. |
| Flash Memory | 32KB HDFlash with read-out protection, 100-program/erase cycles, 40-year data retention at 85°C; supports field firmware updates via IAP. |
| RAM Size | 1024 bytes (1KB) + 256-byte stack; sufficient for real-time task stacks and small buffer arrays in sensor acquisition routines. |
| ADC Resolution | 10-bit SAR ADC with up to 16 input channels; delivers ±1 LSB INL/DNL for precision analog monitoring in motor control feedback loops. |
| Timers | Five independent timers: Main Clock Controller (RTC/beep/clock-out), configurable watchdog, two 16-bit timers (input capture/output compare/PWM), and 8-bit PWM auto-reload timer with 4 outputs; enables multi-channel PWM generation and precise timebase scheduling. |
| Serial Interfaces | SPI (master/slave), SCI (asynchronous UART), and I²C multimaster interface; allows concurrent communication with displays, EEPROMs, sensors, and host controllers without external protocol bridges. |
| Supply Voltage | 3.8 V to 5.5 V operating range; compatible with standard 5V industrial bus rails and tolerant of brown-out conditions down to 3.8V before LVD triggers. |
| Temperature Range | –40°C to +85°C; qualified for deployment in non-automotive industrial enclosures with ambient thermal cycling. |
Pinout & Package
LQFP64 14 × 14 mm package with exposed pad (RoHS-compliant, Pb-free).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD, VSS | Power supply and ground | Dual power domains: VDD supplies core/peripherals; VSS is common reference; decoupling required per datasheet layout guidelines. |
| OSCIN/OSCOUT | Crystal/resonator interface | Connects to external 1–16 MHz crystal or ceramic resonator; internal oscillator circuitry supports startup stabilization and frequency tolerance compensation. |
| RESET | Asynchronous reset input | Active-low, Schmitt-triggered; initiates full hardware reset sequence including register initialization and Flash boot vector fetch. |
| TLI | Top Level Interrupt input | High-priority asynchronous interrupt source with dedicated vector; used for emergency stop signals or critical fault detection in safety-monitored systems. |
| PA0–PA7, PB0–PB7, PC0–PC7, PD0–PD7, PE0–PE7, PF0–PF7 | Multi-function I/O ports | 48 total bidirectional pins; each configurable as GPIO, alternate function (e.g., SCI TX/RX, SPI SCK/MOSI/MISO), or high-sink output (20 mA sink capability on selected pins). |
| AD0–AD15 | ADC input channels | Shared with port pins (e.g., PA0 = AD0); multiplexed analog inputs support single-ended or differential sampling sequences under software control. |
Key Features
| Feature | Design Value |
|---|---|
| In-Application Programming (IAP) | Enables firmware updates over SCI or SPI without external programmer; preserves RAM contents during Flash reprogramming for seamless runtime patching. |
| Enhanced Low Voltage Detector (LVD) | Monitors VDD with programmable threshold (2.8V/3.3V/3.8V/4.3V); generates interrupt or reset on undervoltage, critical for fail-safe shutdown in power-sensitive control logic. |
| Configurable Watchdog Timer | Independent timeout counter with windowed or free-running modes; resets CPU if firmware hangs, with optional interrupt-only mode for diagnostic logging prior to reset. |
| PWM Auto-Reload Timer (ART) | 8-bit timer with 4 independent PWM outputs, 2 input captures, and event-triggered reload; supports motor phase control and LED dimming with synchronized dead-time insertion. |
| Real-Time Clock & Beeper (MCC/RTC) | Integrated RTC with calendar/time-of-day registers and programmable beep generator; eliminates need for external RTC IC in HMI or alarm-based applications. |
Applications
| Industrial Motor Control | Smart Sensor Node |
|---|---|
Use Scenario: Closed-loop speed regulation of 3-phase BLDC motors using Hall-effect feedback and current sensing. IC Role / Device Role / Timing Role: Central controller executing PID loop at 10 kHz, managing six-step commutation via PWM outputs, and reading ADC channels for phase current and temperature. Use Value: Integrated 16-bit timers with input capture enable precise rotor position sampling; 32KB Flash accommodates motor profile tables and safety diagnostics. |
Use Scenario: Battery-powered environmental monitor collecting temperature, humidity, and CO₂ via I²C sensors and transmitting data via SCI to gateway. IC Role / Device Role / Timing Role: Low-power system manager entering Wait mode between 10-second sampling intervals; wakes on timer interrupt to acquire and process sensor data. Use Value: Four power-saving modes reduce active current to 5 mA and standby current to 1.2 µA; integrated ADC eliminates external signal conditioning. |
| Human-Machine Interface (HMI) | Legacy Equipment Retrofit |
Use Scenario: Keypad-driven display panel with backlight dimming, buzzer alerts, and serial configuration interface. IC Role / Device Role / Timing Role: Dedicated UI controller managing matrix keypad scan, PWM-driven LED backlight, and beeper tone generation via MCC/RTC module. Use Value: On-chip beeper and 4-channel PWM eliminate discrete audio drivers; 48 I/O lines support direct connection to 4×4 keypad and 8-segment display. |
Use Scenario: Replacement controller for discontinued PLC I/O modules requiring pin-compatible upgrade with minimal PCB redesign. IC Role / Device Role / Timing Role: Drop-in functional replacement for ST72321R6-series predecessors; retains identical pinout, memory map, and peripheral register layout. Use Value: Binary-compatible firmware execution and identical LQFP64 footprint allow reuse of existing PCBs and toolchains without validation overhead. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ST7FLITE2K4M6 | 20KB Flash, 1.5KB RAM, same ST7 core, LQFP64 package; lacks AVD and TLI pin; lower max clock (8 MHz vs 16 MHz). | Targeted at cost-sensitive consumer appliances with reduced analog monitoring needs and no emergency interrupt requirement. | Select when Flash size and auxiliary voltage detection are non-critical; verify clock budget sufficiency for real-time tasks. |
| STM8S105K4T6C | STM8 core (enhanced ST7 derivative), 16KB Flash, 2KB RAM, 10-bit ADC, 3x timers, SPI/I²C/UART; LQFP32 package (not pin-compatible). | Modernized replacement with higher code density, improved interrupt latency, and extended debug capabilities (SWIM interface). | Choose for new designs requiring longer product lifecycle support and better toolchain integration; requires PCB redesign due to 32-pin footprint. |
Compared with ST72F321R6T6TR, ST7FLITE2K4M6 offers lower memory and missing supervision features but reduces BOM cost, while STM8S105K4T6C delivers architectural upgrades and future-proof tooling at the expense of mechanical compatibility.
Availability
ST72F321R6T6TR is available at Aetrix Electronics and suitable for industrial motor control, smart sensor nodes, human-machine interface panels, and legacy equipment retrofit projects requiring stable component supply and long-term obsolescence mitigation.
Supply support for ST72F321R6T6TR 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 devices, sensors, and analog ICs for industrial, automotive, and consumer markets.
The ST7 family was engineered for cost-effective, deterministic 8-bit control in resource-constrained embedded systems-emphasizing low-power operation, robust peripheral integration, and field-upgradable Flash memory for industrial automation and appliance applications.
FAQ
Does ST72F321R6T6TR support in-circuit debugging?
No, ST72F321R6T6TR does not include on-chip debug hardware such as SWIM or JTAG. Debugging requires external in-circuit emulators compatible with the ST7 architecture, or relies on printf-style UART logging and controlled reset-based breakpoints using the TLI pin. Production firmware must be validated pre-flash using cycle-accurate simulators or evaluation boards with debug headers.
What is the maximum ADC sampling rate achievable?
The ADC achieves up to 1 MSPS conversion rate under optimal conditions: 10-bit resolution, internal clock source, and single-channel sequential mode. With 16-channel scanning and automatic channel sequencing, effective throughput drops to ~62.5 kSPS due to acquisition time and conversion overhead. External trigger synchronization via timer events ensures deterministic sampling jitter below ±100 ns.
Can the PLL be disabled after initialization?
Yes, the PLL can be disabled dynamically via the CLK_CR register's PLLEN bit. Disabling it reverts the CPU clock to the base oscillator frequency (e.g., 8 MHz crystal), reducing power consumption by ~30% in active mode. However, peripherals tied to PLL-derived clocks (e.g., certain timer prescalers) must be reconfigured to avoid timing faults before disabling.
Is the Flash memory endurance sufficient for daily firmware updates?
With 100 program/erase cycles specified, ST72F321R6T6TR Flash is rated for approximately 27 years of daily updates (365 cycles/year). For applications requiring more frequent field updates, use IAP to rewrite only modified sectors-not full Flash-and implement wear-leveling in firmware using reserved memory pages as swap buffers.
ST72F321R6T6TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 64-LQFP
- Series:
- ST7
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Core Processor:
- ST7
- Core Size:
- 8-Bit
- Speed:
- 8MHz
- Connectivity:
- I2C, SCI, SPI
- Peripherals:
- LVD, POR, PWM, WDT
- Number of I/O:
- 48
- Program Memory Size:
- 32KB (32K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 1K x 8
- Voltage - Supply (Vcc/Vdd):
- 3.8V ~ 5.5V
- Data Converters:
- A/D 16x10b
- Oscillator Type:
- Internal
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
ST72F321R6T6TR FAQ
1.How can I place an order for ST72F321R6T6TR through Aetrix?
Please submit a Request for Quotation (RFQ) for ST72F321R6T6TR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ST72F321R6T6TR reliable?
The price and inventory of ST72F321R6T6TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST72F321R6T6TR is usually 5 days.
3.What payment methods are accepted for ST72F321R6T6TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST72F321R6T6TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST72F321R6T6TR?
ST72F321R6T6TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST72F321R6T6TR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ST72F321R6T6TR?
For technical support, including ST72F321R6T6TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST72F321R6T6TR requirements.
6.How does Aetrix verify that ST72F321R6T6TR is sourced from the original manufacturer or authorized distributors?
All ST72F321R6T6TR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ST72F321R6T6TR meets industry standards.
7.What is the process for return or replacement of ST72F321R6T6TR?
All ST72F321R6T6TR units undergo pre-shipment inspection (PSI). If there is an issue with ST72F321R6T6TR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ST72F321R6T6TR part is unused and in its original packaging.
Return procedure for ST72F321R6T6TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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