Dear Readers


In UVM  we keep hearing these terms sequences/sequencer /transaction . lets try to understand these terms as below

-Happy Reading
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Sequencer 

is a stimulus generator which returns random data item when requested by driver.
Sequencer  controls the flow of  sequences from sequencer to the driver

Using sequence we can add constraints to generate controlled randomized values of stimulus..
Transaction is the input to the DUT from driver component and transaction  is a set of sequences



Sequence {provides control on distribution of randomized values} ----> sequencer --(generates randomized stimulus when requested by Driver)----> transaction sent to DUT

 Sequences consist of randomized values of transactions i.e data items or sequence items
 Thus generated  sequences will be sent by the sequencer to the driver upon  request.
 Ultimately these transactions or data items, will be passed on to the DUT after the driver finishes its execution upon transactions.

The Sequences would be executed during the run phase

Sequence has the task_body() where as  the sequencer dont have it !
This is one of the many interview questions which i was asked on UVM.