1. System Overview
1.1 Introduction
System Clock
Configuration
24.5 MHz 2%
Oscillator
CIP-51 8051 Controller
Core
40 KB ISP Flash
Program Memory
256 Byte SRAM
SFR
Bus
2048 Byte XRAM
SYSCLK
Independent
Watchdog
Timer
Power
Net
Voltage
Regulators
VDD
VREGIN
GND
CMOS Oscillator
Input
48 MHz 1.5%
Oscillator
Clock
Recovery
D+
D-
VBUS
USB Peripheral
Controller
Full / Low
Speed
Transceiver
Low Freq.
Oscillator
Charge
Detection
EXTCLK
Power-On
Reset
Supply
Monitor
C2CK/RSTb
Reset
Debug /
Programming
Hardware
C2D
Analog Peripherals
Digital Peripherals
AMUX
Priority
Crossbar
Decoder
Port I/O Configuration
CRC
2 Comparators
12/10 bit
ADC
Temp
Sensor
VREF
VDD
VDD
Internal
Reference
+
-+
-
UART1
Timers 0,
1, 2, 3, 4, 5
3-ch PCA
I2C /
SMBus
SPI
Port 0
Drivers
Port 1
Drivers
P0.n
Port 2
Drivers
P2.n
P1.n
1 KB RAM
Low Power
Crossbar
Control
Config.
Logic
Units (4)
Figure 1.1. Detailed EFM8UB3 Block Diagram
This section describes the EFM8UB3 family at a high level.
For more information on the device packages and pinout, electrical specifications, and typical connection diagrams, see the EFM8UB3
Data Sheet. For more information on each module including register definitions, see the EFM8UB3 Reference Manual. For more infor-
mation on any errata, see the EFM8UB3 Errata.
EFM8UB3 Reference Manual
System Overview
silabs.com
| Building a more connected world.
Rev. 0.2 | 13