hi,

What is BIST ? and why is it required.
If the question is very basic excuse me iam an novice engineer...

Built is self test is a mechanism to test memories. The testing mechanism is to write to the memory, read from the memory and compare the results and publish where the specified memory area is passed or failed.

BIST is a embedded logic to test your chip logic or memory. LogicBIST checks the manufacturing fault on core logic whereas MemoryBIST checks the same on memories.

BIST is a wrapper kind of thing that is built around your Unit Under test (UUT). This wrapper will be coded such that it is transparent in functional mode. The FSM in the BIST logic will generate patterns to be written into the UUT and the Comparator in the logic will compare the UUT response with the expected response. The same comparator will flag a pass/fail signal based on the UUT response.