
440 THE x86 MICROPROCESSORS
that CAS functions as the output enable as well. Some time after the CAS signal is activated,
the data becomes available at the data bus, and the processor needs some time to read it. So
the CAS should remain active until the processor reads it. If CAS is inactivated, the output
buff ers are disabled, and the data is no longer available at the output. However, only after
the CAS signal goes high, can a new cycle start. us, delaying the inactivation of the CAS
signal creates a small delay. If this delay can be avoided, the speed of the memory can be
increased.
In EDO DRAMs, a new cycle can start by inactivating ...