User`s guide
50 • Operation Theory
4.4.2.1 Mode1: Simple Gated-Event Counting
In this mode, the counter counts the number of pulses on the GPTC_CLK
after the software-start. Initial count can be loaded from software. Current
count value can be read-back by software any time without affecting the
counting. GPTC_GATE is used to enable/disable counting. When
GPTC_GATE is inactive, the counter halts the current count value. Figure
31 illustrates the operation with initial count = 5, count-down mode.
5
5
4
3
2
1
1
0
ffff
Gate
CLK
Count value
Software start
Figure 31: Mode 1 Operation
4.4.2.2 Mode2: Single Period Measurement
In this mode, the counter counts the period of the signal on GPTC_GATE in
terms of GPTC_CLK. Initial count can be loaded from software. After the
software-start, the counter counts the number of active edges on
GPTC_CLK between two active edges of GPTC_GATE. After the com-
pletion of the period interval on GPTC_GATE, GPTC_OUT outputs high
and then current count value can be read-back by software. Figure 32 il-
lustrates the operation where initial count = 0, count-up mode.
0
0
1
2
3
4
5
5
5
Gate
CLK
Count value
Software start
Figure 32: Mode 2 Operation