Ddc Signals (Vesa Ddc1/2B); Digital Control Operation - Hitachi 14LD7200 Service Manual

2.3 DDC SIGNALS (VESA DDC1/2B)

This monitor is equipped with VESA DDC 1/2B according to VESA DISPLAY DATA
CHANNEL STANDARD V. 1.0 Rev.1 (tt.mm.199j)
It transmits the EDID-file as a continuous data stream, clocked by V-SYNC (DDC 1); the
controller may increase the Vert. frequency to 25 kHz max. for improved transmission rate.
As an alternative, it sends the EDID-file upon request by the host-system (Read EDID,
Device A0h Start address 00h) in an I
The monitor has installed a 10kΩ pull-up on the SCL-line (pin 15 of 15-pin
VGA-connector).
x0 x1
00: 00 FF
10: 33 0D 01
20: 24 4B 4E AF
30: 01 01
40: 13 00
50: 3C 08
60: 37 4C 44
70: 00 31

2.4 DIGITAL CONTROL OPERATION

Signals used for mode detection:
- Nominal horizontal frequency ( +-0.5 KHz from center frequency)
- Nominal vertical frequency (+-1 Hz from center frequency)
- Horizontal sync. pulse polarity
- Vertical sync. pulse polarity
2.4.1 FACTORY RECALL MODES
Starting the "RECALL" function in the OSD-MENU will clear all old settings of auto
configuration in preset modes.
2.4.2 PROTECTION CIRCUIT
Missing or improper sync pulses will not damage the monitor. Additionally, under these
conditions, the monitor shall not cause damage to the driving source
x2 x3 x4 x5
FF FF FF FF
03 68 25
CE 00
01 01 01 01
71 10 00
DD
00 0A 20 20
34 32 30
0A 20 20 20
2
C compatible format (DDC 2).
x6 x7 x8 x9
FF 00 22 83
17 78 EA C9
01 01 01 01
FA 1E 00 81
00 1C 00 00
20 20 20 20
30 0A 20 20
20 20 20 20
9
xA xB xC xD xE
42 17 01 00
9D A3 59 49
01 01 01 01
51 00 19 30
00 FD 00 32
00 00 00 FC 00
20 20 00 00
20 20 20 20
xF
00 00
96 25
01 01
37 8A
4B 1E
31
00 FF
00 00