PT6553_10 Datasheet, PDF (24/41 Pages) Princeton Technology Corp – LCD Driver IC with Key Input Function

LCD Driver IC with Key Input Function
Tel: [phone]
Fax: [phone]
URL: http://www.princeton.com.tw
PT6553
DISPLAY DATA TRANSFER FROM CONTROLLER
There are three operations involved in the transfer of display data (D1 to D126) to the PT6553. All
display data must be transferred within 30 ms so as to insure and maintain the quality of the displayed
image.
CONTROLLER KEY DATA READ TECHNIQUE
Timer - based key Data Acquisition
The controller makes use of a timer to determine the Key ON/OFF states and to read the key data. The
controller must check every t7 period the DO state when the CE is in the "LOW" state. If the DO is
"LOW", the controller will acknowledge the key that has been pressed and execute the key data read
operation. The t7 must satisfy the following condition:
t7 ≥ (t5 + t6 + t4)
If a key read operation is executed when the DO is in "HIGH" State, the read key data (KD1 to KD30)
and the sleep acknowledge data (SA) will be invalid.
The timer based key data acquisition flowchart is given below.
CE=[L]
No
DO=[L]
Yes
Key Data Read
Processing
PT6553 V1.7
- 24 -
November, 2007