Motore di ricerca datesheet componenti elettronici |
|
AD7147A Scheda tecnica(PDF) 33 Page - Analog Devices |
|
AD7147A Scheda tecnica(HTML) 33 Page - Analog Devices |
33 / 69 page AD7147A Rev. B | Page 32 of 68 SERIAL INTERFACES The AD7147A is available with an SPI interface. The AD7147A-1 is available with an I2C-compatible interface. Both parts are the same, with the exception of the serial interface. SPI INTERFACE The AD7147A has a 4-wire serial peripheral interface (SPI). The SPI has a data input pin (SDI) for inputting data to the device, a data output pin (SDO) for reading data back from the device, and a data clock pin (SCLK) for clocking data into and out of the device. A chip select pin (CS) enables or disables the serial interface. CS is required for correct operation of the SPI. Data is clocked out of the AD7147A on the negative edge of SCLK and data is clocked into the device on the positive edge of SCLK. SPI Command Word All data transactions on the SPI bus begin with the master taking CS from high to low and sending out the command word. This indicates to the AD7147A whether the transaction is a read or a write and provides the address of the register from which to begin the data transfer. The following bit map shows the SPI command word. MSB LSB 15 14 13 12 11 10 9:0 1 1 1 0 0 R/W Register address Bits[15:11] of the command word must be set to 11100 to successfully begin a bus transaction. Bit 10 is the read/write bit; 1 indicates a read, and 0 indicates a write. Bits[9:0] contain the target register address. When reading or writing to more than one register, this address indicates the address of the first register to be written to or read from. Writing Data Data is written to the AD7147A in 16-bit words. The first word written to the device is the command word, with the read/write bit set to 0. The master then supplies the 16-bit input data-word on the SDI line. The AD7147A clocks the data into the register addressed in the command word. If there is more than one word of data to be clocked in, the AD7147A automatically increments the address pointer and clocks the subsequent data-word into the next register. The AD7147A continues to clock in data on the SDI line until either the master finishes the write transition by pulling CS high or the address pointer reaches its maximum value. The AD7147A address pointer does not wrap around. When it reaches its maximum value, any data provided by the master on the SDI line is ignored by the AD7147A. CW 11 CW 10 CW 13 CW 12 SDI CW 15 CW 14 CW 9 CW 7 CW 6 CW 5 CW 4 CW 3 CW 2 CW 1 CW 0 D2 D1 D0 CW 8 t1 t4 16-BIT DATA 5 32 6 7 8 9 10 11 12 13 14 15 16 30 31 t8 t5 SCLK 12 3 4 D15 D14 D13 17 18 19 CS ENABLE WORD R/W REGISTER ADDRESS t2 t3 NOTES 1. SDI BITS ARE LATCHED ON SCLK RISING EDGES. SCLK CAN IDLE HIGH OR LOW BETWEEN WRITE OPERATIONS. 2. ALL 32 BITS MUST BE WRITTEN: 16 BITS FOR THE CONTROL WORD AND 16 BITS FOR THE DATA. 3. 16-BIT COMMAND WORD SETTINGS FOR SERIAL WRITE OPERATION: CW[15:11] = 11100 (ENABLE WORD) CW[10] = 0 (R/W) CW[9:0] = [AD9, AD8, AD7, AD6, AD5, AD4, AD3, AD2, AD1, AD0] (10-BIT MSB-JUSTIFIED REGISTER ADDRESS) 16-BIT COMMAND WORD Figure 48. Single Register Write SPI Timing |
Codice articolo simile - AD7147A |
|
Descrizione simile - AD7147A |
|
|
Link URL |
Privacy Policy |
ALLDATASHEETIT.COM |
Lei ha avuto il aiuto da alldatasheet? [ DONATE ] |
Di alldatasheet | Richest di pubblicita | contatti | Privacy Policy | scambio Link | Ricerca produttore 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 |