Electronic Components Datasheet Search |
|
SC16IS752 Datasheet(PDF) 37 Page - NXP Semiconductors |
|
SC16IS752 Datasheet(HTML) 37 Page - NXP Semiconductors |
37 / 59 page SC16IS752_SC16IS762_7 © NXP B.V. 2008. All rights reserved. Product data sheet Rev. 07 — 19 May 2008 37 of 59 NXP Semiconductors SC16IS752/SC16IS762 Dual UART with I2C-bus/SPI interface, 64-byte FIFOs, IrDA SIR 10.2 Addressing and transfer formats Each device on the bus has its own unique address. Before any data is transmitted on the bus, the master transmits on the bus the address of the slave to be accessed for this transaction. A well-behaved slave with a matching address, if it exists on the network, should of course acknowledge the master's addressing. The addressing is done by the first byte transmitted by the master after the START condition. An address on the network is seven bits long, appearing as the most significant bits of the address byte. The last bit is a direction (R/W) bit. A zero indicates that the master is transmitting (‘write’) and a one indicates that the master requests data (‘read’). A complete data transfer, comprised of an address byte indicating a ‘write’ and two data bytes is shown in Figure 16. When an address is sent, each device in the system compares the first seven bits after the START with its own address. If there is a match, the device will consider itself addressed by the master, and will send an acknowledge. The device could also determine if in this transaction it is assigned the role of a slave receiver or slave transmitter, depending on the R/W bit. Each node of the I2C-bus network has a unique seven-bit address. The address of a microcontroller is of course fully programmable, while peripheral devices usually have fixed and programmable address portions. When the master is communicating with one device only, data transfers follow the format of Figure 16, where the R/W bit could indicate either direction. After completing the transfer and issuing a STOP condition, if a master would like to address some other device on the network, it could start another transaction by issuing a new START. Another way for a master to communicate with several different devices would be by using a ‘Repeated START’. After the last byte of the transaction was transferred, including its acknowledge (or negative acknowledge), the master issues another START, followed by address byte and data without effecting a STOP. The master may communicate with a number of different devices, combining ‘reads’ and ‘writes’. After the last transfer takes place, the master issues a STOP and releases the bus. Possible data formats are demonstrated in Figure 17. Note that the repeated START allows for both change of a slave and a change of direction, without releasing the bus. We shall see later on that the change of direction feature can come in handy even when dealing with a single device. Fig 16. A complete data transfer S P SDA SCL 0 to 6 78 ACK 002aab046 START condition STOP condition address R/W 0 to 6 78 data ACK 0 to 6 78 data ACK |
Similar Part No. - SC16IS752 |
|
Similar Description - SC16IS752 |
|
|
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 |