Datasheet 24C01C (Microchip) - 10

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24C01C 7.0 ACKNOWLEDGE POLLING FIGURE 7-1: ACKNOWLEDGE POLLING FLOW
Since the device will not acknowledge during a write cycle, this can be used to determine when the cycle is complete (this feature can be used to maximize bus throughput). Once the Stop condition for a Write Send command has been issued from the master, the device Write Command initiates the internally timed write cycle. ACK polling can be initiated immediately. This involves the master sending a Start condition followed by the control byte Send Stop for a Write command (R/W = 0). If the device is still Condition to busy with the write cycle, then no ACK will be returned. Initiate Write Cycle If no ACK is returned, then the Start bit and control byte must be re-sent. If the cycle is complete, then the device will return the ACK and the master can then proceed with the next Read or Write command. See Send Start Figure 7-1 for flow diagram. Send Control Byte with R/W = 0 Did Device NO Acknowledge (ACK = 0)? YES Next Operation DS21201K-page 10  1997-2012 Microchip Technology Inc. Document Outline 24C01C Features: Description: Block Diagram Package Types 1.0 Electrical Characteristics Absolute Maximum Ratings(†) TABLE 1-1: DC Characteristics TABLE 1-2: AC Characteristics FIGURE 1-1: Bus Timing Data 2.0 Pin Descriptions TABLE 2-1: Pin Function Table 2.1 SDA Serial Data 2.2 SCL Serial Clock 2.3 A0, A1, A2 2.4 Test 2.5 Noise Protection 3.0 Functional Description 4.0 Bus Characteristics 4.1 Bus Not Busy (A) 4.2 Start Data Transfer (B) 4.3 Stop Data Transfer (C) 4.4 Data Valid (D) 4.5 Acknowledge FIGURE 4-1: Data Transfer Sequence on the Serial Bus FIGURE 4-2: Acknowledge Timing 5.0 Device Addressing FIGURE 5-1: Control Byte Format 5.1 Contiguous Addressing Across Multiple Devices 6.0 Write Operations 6.1 Byte Write 6.2 Page Write FIGURE 6-1: Byte Write FIGURE 6-2: Page Write 7.0 Acknowledge Polling FIGURE 7-1: Acknowledge Polling Flow 8.0 Read Operation 8.1 Current Address Read FIGURE 8-1: Current Address Read 8.2 Random Read 8.3 Sequential Read FIGURE 8-2: Random Read FIGURE 8-3: Sequential Read 9.0 Packaging Information 9.1 Package Marking Information Appendix A: Revision History The Microchip Web Site Customer Change Notification Service Customer Support Reader Response Product Identification System Trademarks Worldwide Sales