The CTS 9513 Counter/Timer

Our CyCTM-series boards are based on the CTS 9513 System Timing Controller chip. This chip replaces the older AMD 9513.

One significant advantage of the CTS 9513 is its higher speed. Instead of the 7MHz limit of the older chip, the CTS 9513 accepts a 20MHz maximum input clock signal, which allows timing resolutions of up to 50ns and gate pulses as short as 50ns.

The CTS 9513 is addressed as two locations: a control port and a data port. The control port provides direct access to the Status register, Command register, and the data-point register. The data port is used to communicate with all other addressable internal locations.

Each of the 5 general-purpose counters is independently controlled by its Counter Mode register. Through this register, you can select one of 16 sources as the counter input, a variety of gating and repetition modes, up or down counting, and active-high or active-low input and output polarities. A Master Mode register controls the options which do not pertain to one of the 5 specific counters.

There are 24 different preset operating modes. They include software and hardware-triggered one-shot pulses. You select Mode A through X by setting 3 bits in the Counter Mode register.

A Load Register and a Hold Register are associated with each counter. The Load register automatically reloads the counter to any predefined value, to control the effective count period. The Hold Register saves intermediate counts without disturbing the count process, or generates complex output waveforms when it is used as a second Load Register.

A powerful command structure simplifies user interaction with the counters. ARM and DISARM commands permit software gating of the count process. The LOAD command reloads the counter with the value stored in either the Load or the Hold register. It may be used as a retrigger or for counter initialization. A SAVE command transfers the contents of a counter to its Hold register. The DISARM command disables further counting. The STEP command increments or decrements the counter. Additional commands are provided to set or clear an output toggle, issue a reset, or clear and set special bits. Detailed information is provided in user manuals.

Counters work best when the inputs have sharp, clean edges. To provide them, our STA 01 Universal Screw Terminal Panel has space for voltage dividers and low-pass filter circuits. To debounce a counter input, populate one of the low-pass filter curcuits and connect it to the counter's input signal.