An improved redundancy architecture for embedded memories in an ASIC chip
includes one or more compiler-generated embedded memory instances. Each
embedded memory instance has a universal register for storing an address
of a defective subunit of the memory instance from a variety of sources.
A control block is located on the ASIC chip outside of the memory
instances. The control block has a defective memory register for storing
an address of a defective memory subunit. The address of a defective
memory subunit from the defective memory register in the control block is
transferred to the universal interface register in the memory instance.
In one embodiment, the control block includes fuses for storing a
defective subunit address in binary form. A fuse array is located outside
of the memory instances and contains laser fuses that represent address
of defective subunits for each memory instance. Alternatively, the
control block includes a BISTDR (built-in, self-test, diagnostic, and
repair) system that provides an address of a defective memory subunit.
Means are provided in the memory instances for comparing incoming memory
addresses to address bits for defective memory subunits stored in each
memory-instance register.