MC145152-2 Parallel-Input (Interfaces with Dual-Modulus Prescalers)

MC145151-2 and MC145152-2 Technical Data, Rev. 5

Freescale Semiconductor

9

N0 - N9

N Counter Programming Inputs (Pins 11 - 20)

The N inputs provide the data that is preset into the

÷ N counter when it reaches the count of 0. N0 is the

least significant digit and N9 is the most significant. Pull-up resistors ensure that inputs left open remain

at a logic 1 and require only a SPST switch to alter data to the zero state.

A0 - A5

A Counter Programming Inputs

(Pins 23, 21, 22, 24, 25, 10)

Section 4.3, “Dual-Modulus Prescaling,” on page 21). The A inputs all have internal pull-up resistors that

ensure that inputs left open will remain at a logic 1.

Reference Oscillator Input/Output (Pins 27, 26)

These pins form an on-chip reference oscillator when connected to terminals of an external parallel

2.2.2

Output Pins

φ

Phase Detector B Outputs (Pins 7, 8)

These phase detector outputs can be combined externally for a loop-error signal.

φ

pulsing low.

φ

minimum time period when both pulse low in phase.

MC

Dual-Modulus Prescale Control Output (Pin 9)

Signal generated by the on-chip control logic circuitry for controlling an external dual-modulus prescaler.

The MC level will be low at the beginning of a count cycle and will remain low until the

÷ A counter has

counted down from its programmed value. At this time, MC goes high and remains high until the

÷ N

counter has counted the rest of the way down from its programmed value (N - A additional counts since

both

÷ N and ÷ A are counting down during the first portion of the cycle). MC is then set back low, the

counters preset to their respective programmed values, and the above sequence repeated. This provides for