16K I2C Serial EEPROM - Hifi-remote.com

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24AA16/24LC16B5.0 ACKNOWLEDGE POLLINGSince the device will not acknowledge during a writecycle, this can be used to determine when the cycle iscomplete (this feature can be used to maximize busthroughput). Once the STOP condition for a write commandhas been issued from the master, the device initiatesthe internally timed write cycle. ACK polling canbe initiated immediately. This involves the master sendinga start condition followed by the control byte for awrite command (R/W = 0). If the device is still busy withthe write cycle, then no ACK will be returned. If thecycle is complete, then the device will return the ACKand the master can then proceed with the next read orwrite command. See Figure 5-1 for flow diagram.6.0 WRITE PROTECTIONThe 24XX16 can be used as a serial ROM when theWP pin is connected to VCC. Programming will beinhibited and the entire memory will be write-protected.FIGURE 5-1:ACKNOWLEDGE POLLINGFLOWSendWrite CommandSend StopCondition toInitiate Write CycleSend StartSend Control Bytewith R/W = 0Did DeviceAcknowledge(ACK = 0)?NoYesNextOperationDS21703B-page 8© 2002 Microchip Technology Inc.
24AA16/24LC16B7.0 READ OPERATIONRead operations are initiated in the same way as writeoperations with the exception that the R/W bit of theslave address is set to ‘1’. There are three basic typesof read operations: current address read, random readand sequential read.7.1 Current Address ReadThe 24XX16 contains an address counter that maintainsthe address of the last word accessed, internallyincremented by ‘1’. Therefore, if the previous access(either a read or write operation) was to address n, thenext current address read operation would access datafrom address n + 1. Upon receipt of the slave addresswith R/W bit set to ‘1’, the 24XX16 issues an acknowledgeand transmits the 8-bit data word. The master willnot acknowledge the transfer but does generate aSTOP condition and the 24XX16 discontinues transmission(Figure 7-1).7.2 Random ReadRandom read operations allow the master to accessany memory location in a random manner. To performthis type of read operation, first the word address mustbe set. This is done by sending the word address to the24XX16 as part of a write operation. After the wordaddress is sent, the master generates a START conditionfollowing the acknowledge. This terminates thewrite operation, but not before the internal addresspointer is set. Then the master issues the control byteagain but with the R/W bit set to a ‘1’. The 24XX16 willthen issue an acknowledge and transmits the 8-bit dataword. The master will not acknowledge the transfer butdoes generate a STOP condition and the 24XX16 discontinuestransmission (Figure 7-2).7.3 Sequential ReadSequential reads are initiated in the same way as a randomread except that after the 24XX16 transmits thefirst data byte, the master issues an acknowledge asopposed to a STOP condition in a random read. Thisdirects the 24XX16 to transmit the next sequentiallyaddressed 8-bit word (Figure 7-3).To provide sequential reads the 24XX16 contains aninternal address pointer which is incremented by one atthe completion of each operation. This address pointerallows the entire memory contents to be serially readduring one operation.7.4 Noise ProtectionThe 24XX16 employs a VCC threshold detector circuitwhich disables the internal erase/write logic if the VCCis below 1.5V at nominal conditions.The SCL and SDA inputs have Schmitt trigger and filtercircuits which suppress noise spikes to assure properdevice operation even on a noisy bus.FIGURE 7-1:CURRENT ADDRESS READBUS ACTIVITYMASTERSTARTCONTROLBYTEDATA (n)STOPSDA LINESPBUS ACTIVITYACKNOACK© 2002 Microchip Technology Inc. DS21703B-page 9
Page 1 and 2: M24AA16/24LC16B16K I 2 C Serial EE
Page 3 and 4: 24AA16/24LC16B1.2 AC Characteristic
Page 5 and 6: 24AA16/24LC16B2.0 FUNCTIONAL DESCRI
Page 7: 24AA16/24LC16B4.0 WRITE OPERATION4.
Page 11 and 12: 24AA16/24LC16B8.0 PIN DESCRIPTIONST
Page 13 and 14: 24AA16/24LC16B8-Lead Plastic Dual I
Page 15 and 16: 24AA16/24LC16B8-Lead Plastic Thin S
Page 17 and 18: 24AA16/24LC16B5-Lead Plastic Small
Page 19 and 20: 24AA16/24LC16BON-LINE SUPPORTMicroc
Page 21 and 22: 24AA16/24LC16BPRODUCT IDENTIFICATIO
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