ml9227 Oki Semiconductor, ml9227 Datasheet - Page 19

• Manufacturer Part Number: ml9227
• Description: 27-bit Duplex/triplex Vfd Controller/driver With Digital Dimming, Adc And Key Scan
• Manufacturer: Oki Semiconductor

The rotary encoder switch function
As Figure 1 shows, the rotary encoder switch circuit is consisted of Phase detection, Interrupt generation, Up/down
counter, Direction latch and Parallel-in serial-out shift register.
1) Phase detection
1-1) Clockwise
When signal A and B input as Figure 2, the phase detection circuit outputs UP signal after the chattering absorption
period. At this time, the output INT also goes to high level, so this signal can be used as an interrupt. The INT stays
High level until the keyscan stop mode is selected.
OKI Semiconductor
chattering absorption time
A
B
UP (internal)
INT
UP/DOWN Counter
A
Figure 2 The Input and Output Timing in Case of Clockwise
Phase Detection
P-in/S-out Shift Register
UP
Q3 Q2 Q1
Figure 1 The Rotary Encoder Switch Circuit
DOWN
B
Direction Latch
R1
Generation
Interrupt
for INT
Output data
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