STTS424E02BDA3E STMICROELECTRONICS [STMicroelectronics], STTS424E02BDA3E Datasheet - Page 34

• Manufacturer Part Number: STTS424E02BDA3E
• Description: Memory module temperature sensor with a 2 Kb SPD EEPROM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

SPD EEPROM operation
5.6
5.6.1
5.6.2
5.6.3
5.6.4
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Read operations - SPD
Read operations are performed independently of whether hardware or software protection
has been set.
The device has an internal address counter which is incremented each time a byte is read.
Random address read - SPD
A dummy Write is first performed to load the address into this address counter (as shown in
Figure
condition, and repeats the Device Select Code, with the RW bit set to 1. The device
acknowledges this, and outputs the contents of the addressed byte. The bus master must
not acknowledge the byte, and terminates the transfer with a Stop condition.
Current address read - SPD
For the Current Address Read operation, following a Start condition, the bus master only
sends a Device Select Code with the RW bit set to 1. The device acknowledges this, and
outputs the byte addressed by the internal address counter. The counter is then
incremented. The bus master terminates the transfer with a Stop condition, as shown in
Figure
Sequential read - SPD
This operation can be used after a Current Address Read or a Random Address Read. The
bus master does acknowledge the data byte output, and sends additional clock pulses so
that the device continues to output the next byte in sequence. To terminate the stream of
bytes, the bus master must not acknowledge the last byte, and must generate a Stop
condition, as shown in
The output data comes from consecutive addresses, with the internal address counter
automatically incremented after each byte output. After the last memory address, the
address counter ‘rolls-over’, and the device continues to output data from memory address
00h.
Acknowledge in read mode
For all Read commands, the device waits, after each byte read, for an acknowledgment
during the 9
time, the device terminates the data transfer and switches to its Standby mode.
14) but without sending a Stop condition. Then, the bus master sends another Start
14, without acknowledging the byte.
th
bit time. If the bus master does not drive Serial Data (SDA) Low during this
Figure
14.
STTS424E02