Question

A computer employs RAM chips of 128 x 8 and ROM chips of 512 x 8. The computer system needs 256 bytes of RAM, 1024 x 16 of ROM, and two interface units with 256 registers each. A memory mapped I/O configuration is used. The two higher-order bits of the address bus are assigned 00 for RAM, 01 for ROM, and 10 for interface registers a) Compute total number of decoders needed for the above Memory System Design. b) Give the memory-address map for each of the memory chips. c) Show the chip layout for the above memory design.

Answer 1

Answer:

Explanation:

RAM chip size = 256*8

Required memory size = 2k bytes = 2*1024 bytes = 2*1024*8 bits

Total number of RAM chip required -

(2*1024*8)/(256*8) = 8 chips

ROM chip size = 1024*8

Required memory size = 4k bytes = 4*1024 bytes = 4*1024*8 bits

Total number of ROM chips required -

(4*1024*8)/(1024*8) = 4 chips