Electronic Components Datasheet Search |
|
DS1086_1203 Datasheet(PDF) 10 Page - Maxim Integrated Products |
|
DS1086_1203 Datasheet(HTML) 10 Page - Maxim Integrated Products |
10 / 15 page Spread-Spectrum EconOscillator 10 ______________________________________________________________________________________ ADDR Register The A0, A1, A2 bits determine the 2-wire slave address. The WC bit determines if the EEPROM is to be written to after register contents have been changed. If WC = 0 (default), EEPROM is written automatically after a WRITE EE command. If WC = 1, the EEPROM is only written when the WRITE EE command is issued. In applications where the register contents are frequently written, the WC bit should be set to 1. Otherwise, it is necessary to wait for an EEPROM write cycle to com- plete between writing to the registers. This also pre- vents wearing out the EEPROM. Regardless of the value of the WC bit, the value of the ADDR register is always written immediately to EEPROM. When the WRITE EE command has been received, the contents of the registers are written into the EEPROM, thus lock- ing in the register settings. RANGE Register This read-only register contains a copy of the factory- set offset (OS). This value can be read to determine the default value of the OFFSET register when program- ming a new master oscillator frequency. WRITE EE Command This command is used to write data from RAM to EEPROM when the WC bit in ADDR register is 1. See the ADDR Register section for more details. Example Frequency Calculations Example #1: Calculate the register values needed to generate a desired output frequency of 11.0592MHz. Since the desired frequency is not within the valid mas- ter oscillator range of 66MHz to 133MHz, the prescaler must be used. Valid prescaler values are 2x where x equals 0 to 8 (and x is the value that is programmed into the P3 to P0 bits of the PRESCALER register). Equation 1 shows the relationship between the desired frequency, the master oscillator frequency, and the prescaler. By trial and error, x is incremented from 0 to 8 in Equation 2, finding values of x that yield master oscilla- tor frequencies within the range of 66MHz to 133MHz. Equation 2 shows that a prescaler of 8 (x = 3) and a master oscillator frequency of 88.4736MHz generates our desired frequency. In terms of the device register, x = 3 is programmed in the lower four bits of the PRESCALER register. Writing 03h to the PRESCALER register sets the PRESCALER to 8 (and 4% peak dither). Be aware that the J0 bit also resides in the PRESCALER register. fMASTER OSCILLATOR = fDESIRED x prescaler = fDESIRED x 2X fMASTER OSCILLATOR = 11.0592MHz x 23 = 88.4736MHz Once the target master oscillator frequency has been calculated, the value of offset can be determined. Using Table 2, 88.4736MHz falls within both OS - 1 and OS - 2. However, choosing OS - 1 would be a poor choice since 88.4736MHz is so close to OS - 1’s mini- mum frequency. On the other hand, OS - 2 is ideal since 88.4736MHz is very close to the center of OS - 2’s frequency span. Before the OFFSET register can be programmed, the default value of offset (OS) f f prescaler f DESIRED MASTER OSCILLATOR MASTER OSCILLATOR X = = 2 (2) (3) STOP CONDITION OR REPEATED START CONDITION REPEATED IF MORE BYTES ARE TRANSFERRED ACK START CONDITION ACK ACKNOWLEDGEMENT SIGNAL FROM RECEIVER ACKNOWLEDGEMENT SIGNAL FROM RECEIVER SLAVE ADDRESS MSB SCL SDA R/W DIRECTION BIT 12 6 7 8 9 12 8 9 3–7 Figure 4. 2-Wire Data Transfer Protocol |
Similar Part No. - DS1086_1203 |
|
Similar Description - DS1086_1203 |
|
|
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 |