Overview Of 8/16-Bit Up/Down Counters/Timers - Fujitsu FR60 Hardware Manual

6.1.1

Overview of 8/16-bit Up/Down Counters/Timers

The 8/16-bit up/down counters/timers consist of six event input pins, two 8-bit up/down
counters, two 8-bit reload/compare registers, and their control circuits.
■ Characteristics of the 8/16-bit Up/Down Counters/Timers
• With the 8-bit count register, counting can be performed in a range between 0 and 255 (decimal
numbers). In 16-bit × 1 operation mode, counting can be performed in a range between 0 and 65535
(decimal numbers).
• The following four count modes can be selected for the count clock:
Count mode
Timer mode
Up/down counter mode
Phase difference count mode (multiply-by-2)
Phase difference count mode (multiply-by-4)
• In timer mode, the count clock can be selected from two internal clocks and input from an internal
circuit.
Count clocks available for selection (for operation at 25 MHz):
80 ns (12.5 MHz: divide-by-2)
320 ns (3.125 MHz: divide-by-8)
• The detection edge of the external pin input signal can be selected in up and in down counting mode.
Detection of trailing edges:
Detection of leading edges
Detection of both trailing and leading edges
Edge detection disabled
• The phase difference counting mode is suitable for counting for an encoder, such as for a motor. Using
one of A phase output, B phase output, and Z phase output as input allows to count rotation angle and
number of rotations easily and with high precision.
• Two different functions can be selected for the ZIN pin (this applies for all modes).
ZIN pin:
Counter clear function
Gate function
• The compare function and reload function are available. These functions can be used separately or
combined. By combining these functions, counting up or down can be performed with an arbitrary
width.
Compare and reload functions:
Compare function (compare interrupt request output)
Compare function (compare interrupt request output and counter clearing)
Reload function (underflow interrupt request output and reloading)
247