EFM8 Universal Bee Family
EFM8UB1 Data Sheet
The EFM8UB1, part of the Universal Bee family of MCUs, is a
KEY FEATURES
multi-purpose line of 8-bit microcontrollers with USB feature set in
small packages.
Pipelined 8-bit C8051 core with 50 MHz
maximum operating frequency
These devices offer high value by integrating an innovative energy-smart USB peripheral
Up to 22 multifunction, 5 V tolerant I/O
interface, charger detect circuit, 8 kV ESD protection, and enhanced high speed commu-
pins
nication interfaces into small packages, making them ideal for space-constrained USB
Low Energy USB with full- and low-speed
applications. With an efficient 8051 core and precision analog, the EFM8UB1 family is
support saves up to 90% of the USB
also optimal for embedded applications.
energy
USB charger detect circuit (USB-BCS 1.2
EFM8UB1 applications include the following:
compliant)
Consumer electronics
USB I/O controls, dongles One 12-bit ADC and two analog
comparators with internal voltage DAC as
Medical equipment
High-speed communication bridge
reference input
Five 16-bit timers
Two UARTs, SPI, SMBus/I2C master/
slave and I2C slave
Priority crossbar for flexible pin mapping
Core / Memory Clock Management Energy Management
High Frequency
CIP-51 8051 Core External CMOS Internal LDO
48 MHz RC Power-On Reset
Oscillator Regulator
(50 MHz)
Oscillator
Flash Program High Frequency
RAM Memory Debug Interface Low Frequency Brown-Out 5 V-to 3.3 V LDO
Memory 24.5 MHz RC
(2304 bytes) with C2 RC Oscillator Detector Regulator
(up to 16 KB) Oscillator
8-bit SFR bus
Serial Interfaces I/O Ports Timers and Triggers Analog Interfaces Security
2 x UART SPI External Timer 16-bit CRC
Pin Reset PCA/PWM ADC Comparator 0
Interrupts 0/1/2
2
I C / SMBus
USB
Internal
General Watchdog
Pin Wakeup Timer 3/4 Comparator 1 Voltage
Purpose I/O
Timer
High-Speed I2C Slave
Reference
Lowest power mode with peripheral operational:
Normal Idle Suspend Snooze Shutdown
silabs.com | Building a more connected world. Rev. 1.2 EFM8UB1 Data Sheet
Feature List
1. Feature List
The EFM8UB1 highlighted features are listed below.
Core:
Timers/Counters and PWM:
Pipelined CIP-51 Core
3-channel Programmable Counter Array (PCA) supporting
Fully compatible with standard 8051 instruction set PWM, capture/compare, and frequency output modes
70% of instructions execute in 1-2 clock cycles 5 x 16-bit general-purpose timers
50 MHz maximum operating frequency Independent watchdog timer, clocked from the low frequen-
cy oscillator
Memory:
Communications and Digital Peripherals:
Up to 16 KB flash memory, in-system re-programmable
from firmware, including 1 KB of 64-byte sectors and 15 USB 2.0-compliant full speed with integrated low-power
KB of 512-byte sectors. transceiver, 4 bidirectional endpoints, and dedicated 1 KB
buffer
Up to 2304 bytes RAM (including 256 bytes standard 8051
RAM, 1024 bytes on-chip XRAM, and 1024 bytes of USB 2 x UART, up to 3 Mbaud
buffer)
SPI Master / Slave, up to 12 Mbps
Power:
SMBus/I2C Master / Slave, up to 400 kbps
5 V-input LDO regulator for direct connection to USB sup-
2
I C High-Speed Slave, up to 3.4 Mbps
ply
16-bit CRC unit, supporting automatic CRC of flash at 256-
Internal LDO regulator for CPU core voltage
byte boundaries
Power-on reset circuit and brownout detectors
Analog:
I/O: Up to 22 total multifunction I/O pins:
12-Bit Analog-to-Digital Converter (ADC)
All pins 5 V tolerant under bias
2 x Low-current analog comparators with adjustable refer-
Flexible peripheral crossbar for peripheral routing
ence
5 mA source, 12.5 mA sink allows direct drive of LEDs
On-Chip, Non-Intrusive Debugging
Clock Sources:
Full memory and register inspection
Internal 48 MHz oscillator with accuracy of 1.5% stand-
Four hardware breakpoints, single-stepping
alone and 0.25% using USB clock recovery
Pre-loaded USB bootloader
Internal 24.5 MHz oscillator with 2% accuracy
Temperature range -40 to 85 C
Internal 80 kHz low-frequency oscillator
Single power supply of 2.2 to 3.6 V or 3.0 to 5.25 V
External CMOS clock option
QSOP24, QFN28, and QFN20 packages
With on-chip power-on reset, voltage supply monitor, watchdog timer, and clock oscillator, the EFM8UB1 devices are truly standalone
system-on-a-chip solutions. The flash memory is reprogrammable in-circuit, providing nonvolatile data storage and allowing field up-
grades of the firmware. The on-chip debugging interface (C2) allows non-intrusive (uses no on-chip resources), full speed, in-circuit
debugging using the production MCU installed in the final application. This debug logic supports inspection and modification of memory
and registers, setting breakpoints, single stepping, and run and halt commands. All analog and digital peripherals are fully functional
while debugging. The on-chip 5V-to-3.3V regulator enables operation from 2.2 V up to a 5.25 V supply. Devices are available in 28-pin
QFN, 20-pin QFN, or 24-pin QSOP packages. All package options are lead-free and RoHS compliant.
silabs.com | Building a more connected world. Rev. 1.2 | 2