IDT5V7855-DPK REVISION A MARCH 11, 2010

6

©2010 Integrated Device Technology, Inc.

IDT5V7855 Data Sheet

EEPROM PROGRAMMABLE PLL DIE FOR LVCMOS CRYSTAL OSCILLATOR

Programming Instructions

The IDT5V7855 registers, along with some control functions, are

written and the EEPROM burned through a serial write using the

CONT and OUT pins. During the programming the CONT pin

functions as a Data input while the OUT pin functions as a Clock

input. The data registers are not addressed individually but are all

written sequentially with the most significant bit first. All registers

must be written when programming the device. The order of registers

/ control bits and the number of bits per register are:

9 bits

Tuning Capacitor Register T[8:0]

19 bits

Fractional Multiplier Register M[18:0]

3 bits

Prescaler Register P[2:0]

3 bits

Factory Test Mode Register F[2:0]

1 bit

PLL Bypass Mode (0 = crystal oscillator connected directly to output divider, 1 = PLL used)

1 bit

Power Down Control (0 = CONT acts as an output enable, 1 = CONT acts as power down)

1 bit

Output Enable Type (0 = synchronous output enable, 1 = asynchronous output enable)

7 bits

Output Divider Register D[6:0]

Table 3E. Register Table

Register

Name

Tuning

Capacitor

Fractional

Multiplier

Prescaler

(P)

Factory Test

Mode

PLL

Mode

Power Down

Control

Output Enable

Control

Output

Divider

# of Bits

9-bit

19-bit

3-bit

3-bit

1-bit

1-bit

1-bit

7-bit

Symbol

T[8:0]

M[18:0]

P[2:0]

F[2:0]

D[6:0]