EFM8BB21F16G-C-QFN20R – Full Device Summary

1. Basic Identification

• Part Number: EFM8BB21F16G-C-QFN20R
• Family: EFM8 Busy Bee Family (EFM8BB2 series)
• Core: Pipelined CIP-51 8051 core
• Max Frequency: 50 MHz
• Instruction Compatibility: Fully compatible with standard 8051 instruction set; 70% of instructions execute in 1–2 clock cycles
• Document: Datasheet Rev. 1.6
• Manufacturer: Silicon Labs
• Qualification: Industrial & consumer grade; automotive variants available separately

2. Memory Specifications

• Flash: 16 KB ISP flash memory (in-system programmable)
• RAM: 2304 bytes total
• Bootloader: Pre‑loaded UART bootloader (erasure optional)

3. Package & Pinout

• Package: 20‑pin QFN (3.0 × 3.0 mm)
• Pin Count: 20 pins
• GPIO: 16 multifunction I/O pins
• Priority crossbar for flexible peripheral pin mapping
• Packaging: Tape‑and‑reel (suffix R)
• RoHS Compliant: Yes, lead‑free

4. Power Management

4.1 Operating Conditions

• Supply Voltage:
• Temperature Range: −40 °C to +85 °C (G‑grade)
• Regulators:

4.2 Power Modes

• Normal, Idle, Suspend, Snooze, Stop, Shutdown
• Typical consumption (VDD = 3.0 V, 25 °C):

5. Clock System

• Internal High‑Speed Oscillators:
• Internal Low‑Frequency Oscillator: 80 kHz RC
• External Clock: CMOS clock input up to 50 MHz
• Clock Divider: 1, 2, 4, 8, 16, 32, 64, 128
• Default Clock: 24.5 MHz / 8

6. Analog Peripherals

• ADC: 12‑bit SAR ADC
• Analog Comparators: 2 low‑power comparators
• Temperature Sensor: On‑chip, non‑intrusive

7. Digital & Timing Peripherals

7.1 Timers & PWM

• PCA: 3‑channel Programmable Counter Array
• General Timers: 5 × 16‑bit timers (Timer0–Timer4)
• Watchdog Timer: Independent, clocked from LF oscillator
• Interrupts: Multiple priority levels; port match, pin wakeup

7.2 Communication Interfaces

• UART: 2 × UARTs up to 3 Mbaud
• SPI: 1 × SPI master/slave up to 12 Mbps
• I2C:
• CRC: 16‑bit CRC unit (CCITT‑16 polynomial)

8. Debug & Programming

• Debug Interface: C2 (2‑wire)
• Flash Programming: In‑system programmable via C2 or UART bootloader

9. Electrical Characteristics

• Absolute Maximum Ratings:
• Thermal Resistance:
• Flash Endurance: 20k–100k write/erase cycles
• Data Retention: 10+ years @ 25 °C

10. Reset & Supervisory Features

• Power‑on reset (POR)
• Brown‑out detector
• External reset pin
• Watchdog reset
• Missing clock detector
• Supply monitor reset
• Software triggered reset

11. Key Applications

• Motor control
• Consumer electronics
• Sensor controllers
• Medical equipment
• Lighting systems
• High‑speed communication hubs
• Battery‑powered embedded systems