Figure 8. FIFOA – B (HFA, AF/AEA) Asynchronous Flag Timing

CLKA

WENA

IRA

A0–A17

CLKB

RENB

ORB

B0–B17

AF/AEA

HFA

W1

WX+1

WX+2

W256

W257

W512–Y

W513–Y

W513

W1

W2

WY+1

WY+2

W257

W258

W512–X

W513–X

A. CSA, CSB = 0, W/RA = 1, W/RB = 0

C. HFB and AF/AEB function in the same manner for FIFO B – A.

B. X is the almost-empty offset and Y is the almost-full offset for AF/AEA.

NOTES: