74HC7030 Datasheet, PDF (17/22 Pages) NXP Semiconductors – 9-bit x 64-word FIFO register; 3-state

Philips Semiconductors
9-bit x 64-word FIFO register; 3-state
APPLICATION INFORMATION
Product specification
74HC/HCT7030
The PC74HC/HCT7030 is easily expanded to increase word length. Composite
DIR and DOR flags are formed with the addition of an AND gate. The basic
operation and timing are identical to a single FIFO, with the exception of an added
gate delay on the flags.
Fig.17 Expanded FIFO for increased word length; 64 words × 18 bits.
This circuit is only required if the SI input is constantly held HIGH, when the FIFO
is empty and the automatic shift-in cycles are started or if SO output is constantly
held HIGH, when the FIFO is full and the automatic shift-out cycles are started
(see Figs 7 and 10).
Fig.18 Expanded FIFO for increased word length.
December 1990
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