Switching Waveforms (continued)
Figure 8. Last Write to First Read Full Flag
ADDITIONAL
LAST WRITE
FIRST READ
READS
FIRST WRITE
R
W
tWFF
FF
tRFF
W
R
EF
Q0–Q8
FL/RT
R,W
Figure 9. Last Read to First Write Empty Flag
LAST READ
FIRST WRITE
ADDITIONAL
WRITES
FIRST READ
tREF
tA
VALID
tWEF
Figure 10. Retransmit [11]
tRTC[12]
tPRT
VALID
tRTR
CY7C421
Notes
11. EF, HF and FF may change state during retransmit as a result of the offset of the read and write pointers, but flags are valid at tRTC.
12. tRTC = tPRT + tRTR.
Document Number: 38-06001 Rev. *H
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