Local variables in a sequence

The local variables in a sequence or properties are similar to local variables in the function or task.

Local variables are dynamically created inside sequence instance and removed at the end of the sequence
Each sequence instance has its copy. Hence, the sequence can not access the local variable declared in another instance.

Local variable in a sequence example-1

Consider a computing unit that reads data from a flip flop in 1 clock cycle, increments read data by 10, and writes it to the SRAM memory after 5 clock cycles.

sequence seq;
  int tmp_data;
  (##1 ff_rdata, tmp_data = ff_rdata) ##5 (sram_wdata == (tmp_data+1));
endsequence

Local variable in a sequence example-2

The local variable declared in the sequence is not accessible from another sequence where it is instantiated.

sequence seqA;
  int tmp_data;
  (##1 ff_rdata, tmp_data = ff_rdata) ##5 (sram_wdata == (tmp_data+1));
endsequence

sequence seqB;
  seqA ##2 (d_data == tmp_data); // tmp_data is not accessible even if seqA is instantiated in the seqB.
endsequence