C8051T321-GM

Overview

The C8051T321-GM is an 8-bit microcontroller from the Silicon Labs C8051T620/1/6/7 & C8051T320/1/2/3 family, featuring a high-speed CIP-51 core with up to 48 MIPS throughput at a 48 MHz clock. It includes up to 64 kB of byte-programmable EPROM code memory and up to 3328 bytes of internal data RAM. The device integrates a USB 2.0 function controller supporting full-speed (12 Mbps) or low-speed (1.5 Mbps) operation with an integrated transceiver and clock recovery. Digital peripherals include 25 port I/O pins, two enhanced UARTs, hardware-enhanced SPI, SMBus, four 16-bit counter/timers, and a 16-bit PCA with five capture/compare modules. Analog features consist of comparators with programmable hysteresis and a built-in temperature sensor.

Feature Summary

• Integrates a USB 2.0 compliant function controller with an on-chip transceiver and clock recovery, eliminating the need for external components.
• Features a pipelined CIP-51 architecture that executes most instructions in one or two system clocks for high processing efficiency.
• Includes flexible digital communication interfaces such as dual enhanced UARTs, hardware-enhanced SPI, and SMBus.
• Provides analog capabilities including comparators with configurable interrupt/reset sources and a built-in temperature sensor.

Applications

• Embedded USB connectivity applications requiring host or device side implementation
• Systems utilizing on-chip debug circuitry for non-intrusive in-system development
• Low-power designs leveraging internal oscillators and power management modes

Procurement Notes

Verify component status before integration, as this series is designated Not Recommended for New Designs. Confirm package availability matches design requirements, specifically QFN-28, QFN-32, or LQFP-32 options. Ensure firmware tools support the specific EPROM programming requirements and C2 interface constraints defined in the datasheet.

Selection Notes

Select this component when legacy EPROM-based USB microcontrollers are required for existing designs. Evaluate the trade-off between the 48 MHz maximum frequency and the available memory configurations. Consider the pin count and peripheral set against application needs, noting that ADC functionality varies by derivative within the family.

Part Context

This part belongs to the C8051T32x series, which shares architectural similarities with the C8051T62x series but differs in specific analog peripheral inclusion. The family is characterized by its robust USB integration and high-speed 8051-compatible core. Designers should reference the specific block diagrams for the T321 variant to confirm peripheral presence compared to other derivatives like the T320 or T322.

Replacement Considerations

Silicon Labs recommends transitioning to newer MCU families due to the 'Not Recommended for New Designs' status. Consult official substitution guides for compatible EFM8 or C8051F series devices that offer updated manufacturing support and modernized feature sets.

FAQ

Does the C8051T321-GM include an onboard ADC?

No, the 10-bit ADC is only included in the C8051T620/6/7 and C8051T320/1 derivatives. The C8051T321 does not feature an onboard ADC.

What is the maximum operating frequency of the C8051T321-GM?

The device supports a maximum clock frequency of 48 MHz, enabling up to 48 MIPS throughput.

How is the USB connection powered in this microcontroller?

The device supports both bus-powered and self-powered configurations via the integrated REG0 voltage regulator, which can be configured based on VBUS detection.