Memory technology #

IM = instruction memory, DM = data memory

RAM = random access memory, ROM = read only memory

EEPROM = electrically erasable programmable read only memory

SRAM = static RAM, DRAM = dynamic RAM

Peak memory bandwidth example #

\( 32\text{ bits} \cdot \frac{1\text{ byte} }{8\text{ bits} } = 4 \text{ bytes} \\ \)
\( 1\text{ MB} = 1,000,000 \text{ bytes} \\ \) \( 1 \text{ Hz} = 1 \text{ cycle/second}\\ \) \( 1 \text{ MHz} = 1,000,000 \text{ cycles/second} \\\) \( 100 \text{ MHz} = 100,000,000 \text{ cycles/second} \\\)

So,

SRAM cycle diagrams #

Anything beginning with an underscore _ means it is active low, activated when 0.

_ce = chip enable, _we 1 = write enable (determines whether in read cycle or write cycle), _oe = output enable.

Tri-state buffer #

hi-Z = high impedance