Overview - Fujitsu F2MC-16LX Hardware Manual

CHAPTER 13 8/16-BIT UP/DOWN COUNTER/TIMER

13.1 Overview

The 8/16-bit up/down counter/timer consists of six event input pins, two 8-bit up/down
counters, eight bit reload/compare registers, and their control circuits.
I Major functions of 8/16-bit up/down counter/timer
• 8-bit count register used for counting in a range of 0 to 256 (in the 16 bits x one operation
mode, counting in a range of 0 to 65535 is possible).
• Four types of count modes can be selected for the count clock.
• Timer mode
• Up/down count mode
• Phase difference decremented mode (two times)
• Phase difference decremented mode (eight times)
• In the timer mode, the count clock (for 16 MHz) is selected from two types of internal clocks:
• 125 ns (8 MHz: frequency divided by 2)
0.5 µs (2 MHz: frequency divided by 8)
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• In the up/down count mode, a detect edge of the external pin input signal may be selected:
• Falling edge detect
• Rising edge detect
• Both falling and rising edges
• Edge detect prohibited
• The phase difference count mode is suitable for counting encoder output such as motor,
where encoder output from phases A, B, and C is used as input, thereby facilitating high-
precision counting of rotation angle and rotations.
• The ZIN pin is used to select from two types of functions:
• Counter clear function
• Gate function
• Compare and reload functions are provided, where each function or a combination of them
are available. Starting both functions allows up/down counting with any time width.
• Compare function (an interrupt is issued during compare)
• Compare function (an interrupt is issued and the counter is cleared during compare)
• Reload function (an interrupt is issued and reloaded during compare)
• Compare and reload functions (an interrupt is issued and the counter is cleared during
compare, and an interrupt is issued and reloaded when an underflow occurs)
• Compare and reload prohibited
• Interrupt generation is controlled individually during compare, a reload (underflow), or an
overflow.
• The count direction flag identifies the count direction of the last counter operation
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