Hitachi NJI-350B - page 220

Chapter 8 High-speed counter, PWM / Pulse train output and Analogue I/O
8-11
(2) Phase counting mode 1
In this mode the counter counts at the rising edge of input 1A. At this point, if input 1B is 0 (Low) it counts up, and if
input 1B is 1 (High) it counts down.
Figure 8.15 Counting operation of phase counting mode 1
Input 1A Input 1B Operation
1 (High) ↑ (Rising edge) Do not count
0 (Low) ↓ (Falling edge)
↓ (Falling edge) 1 (High)
↑ (Rising edge) 0 (Low) Up count
0 (Low) ↑ (Rising edge) Do not count
1 (High) ↓ (Falling edge)
↓ (Falling edge) 0 (Low)
↑ (Rising edge) 1 (High) Down count
(3) Phase counting mode 2
In this mode, if input 1B is 0 (Low) at the rising edge of input 1A the counter counts up, and if input 1A is 0 (Low) at the
rising edge of input 1B, the counter counts down.
Figure 8.16 Counting operation of phase counting mode 2
Input 1A Input 1B Operation
1 (High) ↑ (Rising edge) Do not count
0 (Low) ↓ (Falling edge)
↓ (Falling edge) 1 (High)
↑ (Rising edge) 0 (Low) Up count
0 (Low) ↑ (Rising edge) Down count
1 (High) ↓ (Falling edge) Do not count
↓ (Falling edge) 0 (Low)
↑ (Rising edge) 1 (High)
Coincidence
output
On
p
reset
Off
p
reset
Count value
Input 1B
Input 1A
Coincidence
output
On
p
reset
Off
p
reset
Count
value
Input 1B
Input 1A