Toshiba e-studio550 Service Manual page 80

(3) LCD drive operation
The following describes the drive operation to display the message "READY".
PWA-F-SYS-300
PWA-F-SYS-340
GA
LCD
controller
LED
driver
LED
LCD
PWA-F-DSP-300
PWA-F-DSP-340, PWA-F-MKEY-340, PWA-F-SKEY-340
(4) Data transmission
FRAME
LOAD
FRAME
LOAD
CP
D0-D3
JUNE 2002 © TOSHIBA TEC
System
CPU
(c)
R
(c)
A
M
(d)
(d)
KEY CPU
Key switches
and
touch panel
1/tF
240 1 2
(a) The System CPU requests the
(a)
PROM
(b) The PROM outputs data to display
(b)
(c) The System CPU writes the data to
(d) The LCD controller/driver reads the
240 1 2
CP x(320/4) pulses
5 - 9
PROM data to display "READY".
the message to the System CPU.
be displayed on the LCD into the
RAM.
display data from the RAM, and out-
puts the data to the LCD.
1/tF
240 1
e-STUDIO550/650/810 CONTROL PANEL
2