47L16 datasheet(24/40 Pages) MICROCHIP

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47L04/47C04/47L16/47C16

DS20005371C-page 24

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2.6

ACKNOWLEDGE POLLING

Since the device will not acknowledge during Store and

Recall operations, nor during the internal STATUS

signal can be used to determine when those events are

complete. Once such

event

has started,

Acknowledge polling can be initiated immediately. This

involves the master sending a Start condition, followed

by the write control byte (R/W = 0) for either the SRAM

array or the Control registers. If the device is still busy,

then no Acknowledge will be returned. In this case,

then the Start condition and control byte must be

resent. If the Store or Recall is complete, then the

device will return an Acknowledge, and the master can

then proceed with the next Read or Write command.

See Figure 2-15 for flow diagram.

FIGURE 2-15:

ACKNOWLEDGE

POLLING FLOW

Send Start

Initiate

Store, Recall, or

STATUS Register Write Event

Send Control Byte

with R/W = 0

Did Device

Acknowledge

(ACK = 0)?

Operation

YES

Note:

Either the SRAM or Control register

control byte can be used for Acknowl-

edge Polling

47L16 Datasheet(PDF) 24 Page - Microchip Technology