User manual

D.10 Mode J waveform

Variable Duty Cycle Rate Generator with No Hardware Gating

Mode J will find the greatest usage in frequency generation applications

with variable duty cycle requirements. Once armed, the counter will

count continuously until it is issued a DISARM command.

On the first TC, the counter will be reloaded from the Hold register.

Counting will then proceed until the second TC at which time the

counter will be reloaded from the Load register. Counting will continue,

with the reload source alternating on each TC, until a DISARM

command is issued to the counter. (The third TC reloads form the Hold

Specifying the TC Toggled output in the Counter Mode register can

generate a variable duty cycle output. The Load and Hold values then

directly control the output duty cycle, with high resolution available

when relatively high count values are used.

SOURCE

COUNT

VALUE

TC OUTPUT

TC TOGGLED

OUTPUT

Mode J Waveforms

H H-1 H-2 2 1 L L-2 2 1 0 H H-1

2 1 0

0 L-1 H-2