Overview Of 8/16-Bit Composite Timer - Fujitsu F2MC-8FX Hardware Manual

CHAPTER 16 8/16-BIT COMPOSITE TIMER
16.1

Overview of 8/16-bit Composite Timer

The 8/16-bit composite timer consists of two 8-bit counters and can be used as two 8-bit
timers, or one 16-bit timer if they are connected in cascade.
The 8/16-bit composite timer has the following functions:
• Interval timer function
• PWM timer function
• PWC timer function (pulse width measurement)
• Input capture function
Interval Timer Function (One-shot Mode)
When the interval timer function (one-shot mode) is selected, the counter starts counting from "00
timer is started. When the counter value matches the register setting value, the timer output is inverted, the
interrupt request occurs, and the count operation is stopped.
Interval Timer Function (Continuous Mode)
When the interval timer function (continuous mode) is selected, the counter starts counting from "00
the timer is started. When the counter value matches the register setting value, the timer output is inverted,
the interrupt request occurs, and the count operation is continued from "00
square wave as a result of this repeated operation.
Interval Timer Function (Free-run Mode)
When the interval timer function (free-run mode) is selected, the counter starts counting from "00
the counter value matches the register setting value, the timer output is inverted and the interrupt request
occurs. When the counter continues to count until reaching "FF
continue the counting operation. The timer outputs a square wave as a result of this repeated operation.
PWM Timer Function (Fixed-cycle Mode)
When the PWM timer function (fixed-cycle mode) is selected, a PWM signal with a variable "H" pulse
width is generated in fixed cycles. The cycle is fixed to "FF
16-bit operation. The time is determined by the count clock selected. The "H" pulse width is specified by
setting a register.
PWM Timer Function (Variable-cycle Mode)
When the PWM timer function (variable-cycle mode) is selected, two 8-bit counters are used to generate an
8-bit PWM signal in any cycles and duty depending on the cycle and "L" pulse width specified by registers.
In this operation mode, the composite timer cannot serve as a 16-bit counter, as two 8-bit counters are used.
232
" again. The timer output a
H
", it restarts counting from "00
H
" during 8-bit operation or "FFFF
H
" as the
H
" as
H
". When
H
" to
H
" during
H