Preliminary Data Sheet #: TM055

Page 9 of 24

Rev: P00

Date: 5/17/04

© Copyright 2004 The Connor-Winfield Corp.

Master/Slave Operation

During master operation, the master pays no attention to the Slave Input reference other than monitoring it for qualification

purposes. If the slave unit is removed, there is no behavioral change in the master.

During slave operation, the slave module locks to the Slave Input reference from the master, and continually qualifies it. If the

slave module determines that the master input has gone out of range, the slave continues to lock to the master until it reaches the

end of its pull-in/hold-in range, which is approximately ±125 ppm. If the slave determines that the Slave Input frequency from the

master has been removed, the slave will use its internal priority table (which should be configured the same as the master module)

and configuration registers to begin locking to the highest priority qualified reference (or to the selected input reference if the master

unit was in manual mode). As soon as the Slave Input from the master returns, (after a 10 sec. minimum soak time) the slave will

begin locking to it.

When the module is in slave mode, the external indicator pins (Reference 1-Reference 6, Free Run, Hold Over) will remain

low, regardless of the mode. If the module is locked to or is attempting to lock to the master, the alarm indicator will be low. The

LOCK alarm works normally as long as the module is tracking the master. If the master is lost (due to LOR or out of tracking range),

and the module enters another mode, the alarm and LOCK indicators will both remain high (=1). The internal PLL status register

(0Eh) must be read to determine the current mode of operation of the module.

The goal of the slave is to maintain a zero-phase error with the Slave Input from the master. In order to accomplish this, the BW

during slave mode is increased so that the slave can respond very quickly to any change in the master's frequency to minimize the

phase difference between master and slave.

Master Mode

Slave Mode

Slave mode is selected

Master mode is selected

Master/Slave State Diagram

Figure 5