Electronic Components Datasheet Search |
|
ADT7476 Datasheet(PDF) 11 Page - ON Semiconductor |
|
ADT7476 Datasheet(HTML) 11 Page - ON Semiconductor |
11 / 67 page ADT7476 http://onsemi.com 11 pulse to assert a stop condition. In read mode, the master device overrides the acknowledge bit by pulling the data line high during the low period before the ninth clock pulse. This is known as no acknowledge. The master then takes the data line low during the low period before the 10th clock pulse, and then high during the 10th clock pulse to assert a stop condition. Any number of bytes of data can be transferred over the serial bus in one operation. However, it is not possible to mix read and write in one operation because the type of operation is determined at the beginning and cannot subsequently be changed without starting a new operation. In the ADT7476, write operations contain either one or two bytes, and read operations contain one byte. To write data to one of the device data registers or read data from it, the address pointer register must be set so the correct data register is addressed. Then, data can be written into that register or read from it. The first byte of a write operation always contains an address stored in the address pointer register. If data is to be written to the device, then the write operation contains a second data byte that is written to the register selected by the address pointer register. This write operation is illustrated in Figure 18. The device address is sent over the bus, and then R/W is set to 0. This is followed by two data bytes. The first data byte is the address of the internal data register to be written to, which is stored in the address pointer register. The second data byte is the data to be written to the internal data register. When reading data from a register, there are two possibilities: 1. If the ADT7476’s address pointer register value is unknown, or not the desired value, then it must first be set to the correct value before data can be read from the desired data register. This is done by performing a write to the ADT7476 as before, but only the data byte containing the register address is sent, because no data is written to the register (see Figure 19). A read operation is then performed consisting of the serial bus address; R/W bit set to 1, followed by the data byte read from the data register (see Figure 20.) 2. If the address pointer register is already known to be at the desired address, data can be read from the corresponding data register without first writing to the address pointer register (see Figure 20). It is possible to read a data byte from a data register without first writing to the address pointer register, if the address pointer register is already at the correct value. However, it is not possible to write data to a register without writing to the address pointer register, because the first data byte of a write is always written to the address pointer register. In addition to supporting the send byte and receive byte protocols, the ADT7476 also supports the read byte protocol. See Intel’s System Management Bus Specifications Revision 2 for more information. If several read or write operations must be performed in succession, the master can send a repeat start condition instead of a stop condition to begin a new operation. Figure 18. Writing a Register Address to the Address Pointer Register, then Writing Data to the Selected Register R/W 0 SCL SDA 1 0 1 1 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 START BY MASTER 19 1 ACK. BY ADT7476 9 D7 D6 D5 D4 D3 D2 D1 D0 STOP BY MASTER 1 9 SCL (CONTINUED) SDA (CONTINUED) FRAME 1 SERIAL BUS ADDRESS BYTE FRAME 2 ADDRESS POINTER REGISTER BYTE FRAME 3 DATA BYTE Figure 19. Writing to the Address Pointer Register Only R/W 0 SCL SDA 10 1 1 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 STOP BY FRAME 1 SERIAL BUS ADDRESS BYTE FRAME 2 ADDRESS POINTER REGISTER BYTE 1 1 9 9 ACK. BY ADT7476 ACK. BY ADT7476 START BY MASTER ACK. BY ADT7476 ACK. BY MASTERMASTER |
Similar Part No. - ADT7476 |
|
Similar Description - ADT7476 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |