A computer has a $$256$$ $$K$$ Byte, $$4$$-way set associative, write back data cache with block size of $$32$$ Bytes. The processor sends $$32$$ bit addresses to the cache controller. Each cache tag director $$y$$ entry contains, in addition to address tag, $$2$$ valid bits. $$1$$ modified bit and $$1$$ replacement bit.

The number of bit in the tag field of an address is

A computer has a $$256$$ $$K$$ Byte, $$4$$-way set associative, write back data cache with block size of $$32$$ Bytes. The processor sends $$32$$ bit addresses to the cache controller. Each cache tag director $$y$$ entry contains, in addition to address tag, $$2$$ valid bits. $$1$$ modified bit and $$1$$ replacement bit.

The size of the cache tag directory is

An $$8KB$$ direct-mapped write-back cache is organized as multiple blocks, each of size $$32$$-bytes. The processor generates $$32$$-bit addresses. The cache controller maintains the tag information for each cache block comprising of the following.
$$\,\,\,\,$$$$1$$ Valid bit
$$\,\,\,\,$$$$1$$ Modified bit

As many bits as the minimum needed to identify the memory block mapped in the cache.

What is the total size of memory needed at the cache controller to store meta-data (tags) for the cache?

A computer system has an $$L1$$ cache, an $$L2$$ cache, and a main memory unit connected as shown below. The block size in $$L1$$ cache is $$4$$ words. The block size in $$L2$$ cache is $$16$$ words. The memory access times are $$2$$ nanoseconds, $$20$$ nanoseconds and $$200$$ nanoseconds for $$L1$$ cache, $$L2$$ cache and main memory unit respectively.

When there is a miss in both $$L1$$ cache and $$L2$$ cache, first a block is transferred from main memory to $$L2$$ cache, and then a block is transferred from $$L2$$ cache to $$L1$$ cache.
What is the total time taken for these transfers?