ML9092-01TB datasheet(51/66 Pages) OKI

51 / 66 page

FEDL9092-01

OKI Semiconductor

ML9092-01/02/03/04

51/66

1-2) Counterclockwise Rotation

When the A and B signals are input as shown in Figure 4, the phase detection circuit outputs the

DOWN signal after the chattering absorption period. At this time, the KREQ output goes to a

high level, so that this signal can be used as the interrupt signal. The KREQ signal maintains a

high level until the rotary encoder read instruction is executed.

Figure 5 Input/Output Timing for Counterclockwise Rotation

2) UP/DOWN Counter

The UP/DOWN counter is incremented when an UP signal is input and decremented when a DOWN

signal is input. However, if the counter reaches “0111” and an UP signal is input, the UP/DOWN

counter will hold “0111”. In the same manner, if the UP/DOWN counter is at “1000” and a DOWN

signal is input, the UP/DOWN counter will hold “1000”.

Figure 6 When the Up Counter Overflows

Figure 7 When the Down Counter Overflows

KREQ

Chattering absorption period

DOWN (internal signal)

Q4, Q3, Q2, Q1

0001

0010

0011

0100

0101

0110

0111

Q4, Q3, Q2, Q1

1111

1110

1101

1100

1011

1010

1001

1000

ML9092-01TB Datasheet(PDF) 51 Page - OKI electronic componets