LC75804E, LC75804W
2. Interrupt based key data acquisition
(1) Flowchart
CE = [L]
NO
DO = [L]
YES
Key data read
processing
Wait for at
least t10
CE = [L]
NO
DO = [H]
YES
Key OFF
(2) Timing chart
Key on
Key on
Key input
Key scan
t5
t5
t6
t5
CE
t8
t8
t8
t8
DI
t7
Key address
Key data read
t7
t7
t7
DO
Key data read request
t10
Controller
determination
(Key on)
Controller
determination
(Key off)
Controller
determination
(Key on)
t10
Controller
determination
(Key on)
t10
Controller
determination
(Key on)
t10
Controller
determination
(Key off)
t5: Key scan execution time when the key data agreed for two key scans. (615T(s))
t6: Key scan execution time when the key data did not agree for two key scans and the key scan was executed again. (1230T(s))
t7: Key address (43H) transfer time
1
T = 鈥斺€斺€?/div>
t8: Key data read time
fosc
No. 6266-36/37
prev
next