| VGS= | OV | | | | | | | |
| ID = 1/21D Dii eo Tocf | | | | | | | |
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Wait Support: The DP8420A/21A/22A have wait support available as DTACK or WAIT. Both are programmable. DTACK, Data Transfer ACKnowledge, is useful for processors whose wait signal is active high. WAIT is useful for those processors whose wait signal is active low. The user can choose either at programming. These signals are used by the on chip arbi- ter to insert wait states to guarantee the arbitration between accesses, refreshes and precharge. Both signals are inde- pendent of the access mode chosen and both signals can be dynamically delayed further through the WAITIN signal to the DP8420A/21A/22A.