ml670100 Oki Semiconductor, ml670100 Datasheet - Page 111

• Manufacturer Part Number: ml670100
• Description: Ml670100 Is A High-performance 32-bit Microcontroller
• Manufacturer: Oki Semiconductor

7.4
7.4.1
Flexible Timer (FTM) channels 0 and 1 support external clock signals. Figure 7.15 shows the
timing with which the timer channel samples the external clock signal from Timer Clock Input
n pin (TMCLK[n], n=0,1) and uses transitions over the sampling interval to derive the count
clock for incrementing Timer Counter n (TMnC,n=0,1). Sampling is always at the rising edges
of the system clock (SYSCLK) signal; incrementing, two SYSCLK rising edges later. If the
TMCLK field in Timer Control Register n (TMnCON, n=0,1) specifies rising edges of the
external clock signal, a transition from "L" level to "H" level produces a count clock pulse. If
TMCLK specifies falling edges, a transition from "H" level to "L" level produces a count clock
pulse.
The TMCLK[n] (n=0,1) input signal must have "H" level and "L" level pulses that are at least
two system clock (SYSCLK) cycles long.
Signal Timing
Timer Clock Input Sampling
TMnC
Count clock
for TMnC
TMnC
Figure 7.15 : Timing for Sampling External Clock Signal and Incrementing TMnC
TMCLK[n]
TMCLK[n]
SYSCLK
(CLKOUT)
Count clock
for TMnC
SYSCLK
(CLKOUT)
(b)TMCLK specifies falling edges
(a)TMCLK specifies rising edges
Counter value
Counter value
Counter value + 1
Counter value + 1
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