AN921 Datasheet, PDF (1/24 Pages) Silicon Laboratories – Configurable Logic Unit

AN921: Configurable Logic Unit
The EFM8LB1 and EFM8BB3 family of MCUs contain Configura-
ble Logic Units (CLUs) that can be applied to applications that re-
quire some form of programmable logic.
This document demonstrates how to use CLUs to implement the following functions:
• SR latch
• D latch
• Button debounce
• Manchester encoder/decoder
• Biphase Mark encoder/decoder
KEY POINTS
• Configurable Logic operates without CPU
intervention.
• Each unit supports 256 different
combinatorial logic functions, such as
AND, OR, XOR, and multiplexing.
• Multiple units combined can implement
latches, encoders, and decoders.
External Pins
Timer Overflow Pulses
PCA Channels
CLU Asynch Outputs
External Pins
ADC0 ADBUSY Flag
PCA Channels
CLU Asynch Outputs
Carry from CLU[n-1]
(CLU3 carries to CLU0)
SYSCLK
Timer Overflow (ALTCLK)
Input Mux A
Input Mux B
CnEN
CnEN
CnEN
CLUn
Carry to CLU[n+1]
Look
Up
Table
(LUT)
OEN
CnEN
CnEN
DQ
CE
CLR
Q
RST
Output
Selection
SYSCLK
CLUnOUT
Asynchronous Output
(to other CLUs)
CnOUTa
Synchronizer
Synchronous
Output
(to peripherals)
CnOUT
Clock
Polarity
Clock
Selection
silabs.com | Smart. Connected. Energy-friendly.
Rev. 0.1