Edid Data Read/Write - NEC MultiSync LCD2080UX -BKA Service Manual

2.7.5 EDID DATA read/write

Table 2.7.5 Control Terminals of the EEPROM (IC8A1 / IC8F1)
DVI-I
DIGITAL
Reading
DVI-I
from
ANALOG
EEPROM
DVI-D
DSUB
DVI-I
DIGITAL
DVI-I
Writing in
ANALOG
EEPROM
DVI-D
DSUB
When writing EDID of DVI-D, the data input from the D-SUB should be entered. For both INPUT1 and
INPUT2, the DDC-CI commands for writing should be as shown below.
1) Enter the Factory mode.
2) Send a cancel command of WRITE PROTECT. (6E-51-85-C8-03-7E-00-01-CHK)
3) Send a DIGITAL Select command. (6E-51-85-C8-02-36-00-01-CHK)
4) Write the EDID data of DIGITAL.
5) Send an ANALOG Select command. (6E-51-85-C8-02-36-00-00-CHK)
6) Write the EDID data of ANALOG.
7) Turn off the power supply.
IC8A1 IC8F1
DDCENA DDCENA
10pin 10pin
H L
H L
L H
L H
− −
− −
− −
− −
IC8A1 IC8F1
DUALPCB DUALPCB
12pin 12pin
−
H
−
H
H L
H L
−
H
−
H
H H
H H
7-9
IC8A1 IC8F1
BANKSEL BANKSEL
11pin 11pin
−
H
−
L
−
H
−
L
−
H
−
L
−
H
−
L
CPU CPU
/DVISEL1 /WP
P21 P20
L L
L L
H L
H L
L H
L H
H H
H H