datasheetbank_Logo
Integrated circuits, Transistor, Semiconductors Search and Datasheet PDF Download Site

LC75804E View Datasheet(PDF) - SANYO -> Panasonic

Part Name
Description
View to exact match
LC75804E Datasheet PDF : 37 Pages
First Prev 31 32 33 34 35 36 37
LC75804E, LC75804W
Notes on the controller key data read techniques
1. Timer based key data acquisition
(1) Flowchart
CE = [L]
DO = [L]
NO
YES
Key data read
processing
(2) Timing chart
Key input
Key on
Key on
Key scan
CE
DI
DO
t5
t6
t5
t5
t8
t8
Key address
t7
t7
Key data read
t8
t7
Key data read request
t9
Controller
determination
(Key on)
t9
Controller
determination
(Key on)
t9
Controller
determination
(Key off)
t9
Controller
determination
(Key on)
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
t8: Key data read time
1
T = ———
fosc
(3) Explanation
In this technique, the controller uses a timer to determine key on/off states and read the key data. The controller must
check the DO state when CE is low every t9 period without fail. If DO is low, the controller recognizes that a key has
been pressed and executes the key data read operation.
The period t9 in this technique must satisfy the following condition.
t9>t6+t7+t8
If a key data read operation is executed when DO is high, the read key data (KD1 to KD30) and sleep acknowledge
data (SA) will be invalid.
No. 6266-35/37
 

Share Link: 

datasheetbank.com [ Privacy Policy ] [ Request Datasheet ] [ Contact Us ]