MA7001 Datasheet, PDF (7/15 Pages) Dynex Semiconductor – Radiation Hard 512x9 Bit FIFO

MA7001
MODES OF OPERATION
Single Device Mode:
The single device mode is used with Xl grounded. (See Figure
10). In this mode the retransmit facility may be used to re-read
the data when less than 512 have been performed between
resets.
Width Expansion Mode:
In this mode two or more devices are used, depending on the
word length required, with the same control inputs applied to
each. The same operations are applied to all devices, thus
warning flags EF and FF are available from any or all of the
devices. Output Signals from devices in this mode should not
be merged. Figure 11 illustrates two devices configured in
width expansion mode to give an 18 bitword, (512 x 18).
Depth Expansion Mode:
This has applications where more than 512 words are
required. The RETRANSMIT facility is not available in this
mode.
Two or more devices are organised in a daisy chain. The first
device in the chain has FL grounded, all others have FL in high
states. XO of each device is connected to XI of the next device
in the chain.
The same read, write and reset signals are applied to each
device. External logic is required to form new empty and full
flags, i.e. all EF’s are ORed together and all FF’s are ORed
together to form new empty and full flags respectively.
Figure 12 illustrates depth expansion of 2 devices (1024 x 9).
Figure 10: Single Device Mode (512 x 9 bits)
Figure 11: Width Expansion Mode (512 x 18 bits)
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