NEC LCD1550X-BK, Service Manual

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1.5.1 DDC switching control function
Function
When the A5V_OR_DVI power (refer to next page) or DVI SELECT in OSM function is
changed, the X9116WM-2.7 (IC106) pin 5 Rw (Wiper Terminal) output, NJM319V pin 12 OUT-
PUT 1 output (A2_DIG) and pin 7 OUTPUT 2 output (A2_ANA) are set to the following values.
The DIGITAL EEPROM or ANALOG EEPROM slave address is set with this, and the EEPROM
set in the A0 address is validated.
The X9116WM-2.7 control is set in the following order with the 3-Wire Serial Interface (U/D,
/INC, /CS).
µ
-COM Pin No.
67
66
1
21
28
I/O
O
O
O
I
I
Signal name Remarks Function
U/D
/INC
/CS
A2_DIG
A2_ANA
UP/DOWN CONTROL OUTPUT
INCREMENT CONTROL OUTPUT
CHIP SELECT OUTPUT
EEPROM for DIGITAL A2-ADDRESS SENSE
EEPROM for ANALOG A2-ADDRESS SENSE
X9116WM-2.7
X9116WM-2.7
X9116WM-2.7
NJM319V
NJM319V
List of control signals
1
2
3
4
5
R
W
W
R
W
A2_DIG, A2_ANA PORT
U/D PORT
/INC PORT
A2_DIG, A2_ANA PORT
/INC, /CS PORT
A2_DIG, A2_ANA = Previously stored value
U/D = Lo (decrement)
/INC = Transmission Lo ( clock) x 16 times
A2_DIG = Hi, A2_ANA = Lo
/INC = Hi, /CS = Transmition Hi ( clock)
Settling confirmation
Tap slide direction
Number of tap slides
Setting confirmation
Tap position store
Settling confirmation
Tap slide direction
Number of tap slides
Setting confirmation
Tap position store
Set value/status value
Set value/status value
Remarks
When DIGITAL is selected for DVI-I
1
2
3
4
5
R
W
W
R
W
A2_DIG, A2_ANA PORT
U/D PORT
/INC PORT
A2_DIG, A2_ANA PORT
/INC, /CS PORT
A2_DIG, A2_ANA = Previously stored value
U/D = Hi (increment)
/INC = Transmission Lo ( clock) x 16 times
A2_DIG = Lo, A2_ANA = Hi
/INC = Hi, /CS = Transmition Hi ( clock)
Remarks
When ANALOG is selected for DVI-I
OSM DVI SELECT
When DIGITAL is selected
When ANALOG is selected
Rw
Lo
Hi
A2_DIG
Hi
Lo
A2_ANA
Lo
Hi
ANA E2PROM ADDRESS
A8 (invalid)
A0 (valid)
DIG EEPROM address
A0 (valid)
A8 (invalid)
* When the monitor power is ON, the value (DIGITAL or ANALOG) set in the initialization EEPROM is set.