HT62104 HOLTEK [Holtek Semiconductor Inc], HT62104 Datasheet - Page 7

• Manufacturer Part Number: HT62104
• Description: Infrared Remote Encoder
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

Overlapped Key Input Transmission
When two key input trigger pulses overlap, the time where the second trigger pulse occurs will determine what
frame code will be output on the DOUT pin. If the second trigger pulse occurs during the gap time, the following
frame code will be output on the DOUT pin and will be a combination of the two triggered frame codes. The
following diagram shows the transmission waveform.
If the second available trigger pulse occurs during the frame code transmission duration, the present frame code
being transmitted will still be output on the DOUT pin. Here the combination of the two triggered frame codes will
be consecutively output. The following diagram indicates the transmission waveform.
The same methodology can be applied on the rising transition of any available trigger pulses to see how the frame
code changes when overlapping key inputs occur.
Rev. 1.00
DOUT
DOUT
LED
LED
IRC
IRC
K 1
K 2
K 1
K 2
f
f
OSC
OSC
= 455 kHz
= 455 kHz
Overlapping Key Inputs Occurring During a Frame Code Transmission
Overlapping Key Inputs Occurring During the Gap Time
FC 1 : Key 1 Frame Code.
FC 2 : Key 2 Frame Code.
K1
K1
FC 1 : Key 1 Frame Code.
FC 2 : Key 2 Frame Code.
K1
K1
K1+K2
Gap Time
Gap Time
K1
K1+K2
K1+K2
7
FC 1 + FC 2 : Combination of Key 1 and
Key 2 Frame Codes .
FC 1 + FC 2 : Combination of Key 1 and
Key 2 Frame Codes.
K1+K2
K1+K2
K1+K2
K2
K2
K2
K2
K2
May 07, 2012
HT62104