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March 28, 2002
Complete upheaval of the memory system. Instead of strictly
having either a RAM module, or a PROM module, we have designed
a RAM / PROM hybrid memory system. Now we can use PROM to
store our fixed program, and use RAM to store temporary data.
The selection between PROM and RAM is determined by the address
going to the memory unit. We used a DEMUX that controls where
to read data from. Listed below is our specifications:
000000 000000 - 000000 111111 ---> Read from PROM
Greater than 000000 111111 ---> Read from RAM
If any of the upper 6 bits has a 1, then the DEMUX will activate
memory to be read from RAM, else it will be read from PROM.
So our PROM is actually 6 bits in size, and the RAM is 12
bits in size. There will always be output coming from this
device, but LOAD_MBR is the only event that can send it to
MBR.
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