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Key Input, Key Scan Timing
The following are the two basic methods of loading key data.
(1)
Use software to set the key timing output port (port pins T0~T7) as the key source.
(2)
Use hardware to set the LCD segment outputs (S30/KR
Select the appropriate method for the system.
1. Key Input Port
This is a 4 bit, input-only port mainly used when loading key data by software scanning. To read the key
input pin data into data memory, execute the IN2 instruction with the operand [C
2. Key Scan Enable Bit
This bit sets the key scan method.
This bit sets the key loading method.
0: Uses software to set the key timing output port (port pins T0~T7) as the key source.
1: Uses hardware to set the LCD segment outputs (S30/KR
~S23/KR
) as the key source.
0
7
~S23/KR
0
35
TC9314F
= 8].
N
) as the key source.
7
2003-07-03
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