Input Signal Presence Judgment Function - NEC LCD1550X Service Manual

1.4.6

Input signal presence judgment function

List of control signals
µ-COM Pin No.
I / O
I / O
47 ~ 51
I
3
I
18
I
2
I
5
I
20
I
4
I
64
O
63
O
65
O
52
Function
• Analog input signal presence judgment
When using analog signals, it is judged that an input is present when the input signal judgment
conditions shown below are satisfied. The input signal presence judgment is carried out con-
stantly. To comply with automatic input signal (Ch) switching, the input signal presence judg-
ment of signals not displayed or selected (DVI-I
frequency is measured separately by hardware such as the microcomputer counter and ASIC
counter hardware, so there is no problem in the processing speed.)
• If AV* (ASIC) > 10Hz (Results of simple frequency measurement by ASIC) Then
• If C/S_H* (µ-COM) > 10kHz (Free run µ-COM counter, interrupt with 1H. Interrupt cycle is
• If C/S_V* (µ-COM) > 10Hz (Free run µ-COM counter, interrupt with 1V. Interrupt cycle is
• If S/G_H* (µ-COM) > 10kHz (Free run µ -COM counter, interrupt with 1H. Interrupt cycle is
* indicates the video input signal (Ch). The DVI-I connector side is 1, and the D-SUB connec-
tor side is 2.
Input signal judgement condition
AV*
Signal name
ASIC control
MS*,RSTN
C / S_H1 H measurement at H, V Sep. and C / S
V measurement at C / S
C / S_V1
S / G_H1 H measurement at S / G
H measurement at H, V Sep. and C / S
C / S_H2
C / S_V2 V measurement at C / S
H measurement at S / G
S / G_H2
SCDT TMDS SYNC DETECT
TMDS output buffer power save
/ PDO
TMDS internal logic power save
/ PD
TM3_3V power supply OFF : Lo / ON :Hi
P_TMDS
Min. 2msec) Then
1V) Then or X.
Min. 2msec) Then
C / S_H* C / S_V*
Other than the above
Function
D-SUB) is also carried out constantly. (The
or X.
or X.
S / G_H*
Input signal
No input signal
1 - 18
Remarks
ASIC
DVI-I(A)
DVI-I(A)
DVI-I(A)
D-Sub
D-Sub
D-Sub
SiI143CT100
SiI143CT100
SiI143CT100
SI3033LSA
or X.
C / S
S / G
H, V Sep.
S / G
C / S
S / G
C / S
H, V Sep.
C / S