CY7C421-20JC 参数 Datasheet PDF下载

CY7C419/21/25/29/33

Switching Waveforms

(continued)

Last Write to First Read Full Flag

ADDITIONAL

READS

LAST WRITE

R

FIRST READ

FIRST WRITE

W

t

WFF

FF

t

RFF

C420–12

Last Read to First Write Empty Flag

LAST READ

W

FIRST WRITE

ADDITIONAL

WRITES

FIRST READ

R

t

REF

EF

t

A

VALID

VALID

t

WEF

DATA OUT

C420–13

Retransmit

[13]

t

RTC

[14]

t

PRT

FL/RT

R,W

t

RTR

C420–14

Notes:

13. EF, HF and FF may change state during retransmit as a result of the offset of the read and write pointers, but flags will be valid at t

RTC

.

14. t

RTC

= t

PRT

+ t

RTR

.

Document #: 38-06001 Rev. *A

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