- SS-HQ1 Application Notes -
Ver.1.0.0 January 7, 2005
189
12.2.2. Parameters used to set external synchronization
The following two parameters are used to set external synchronization modes.
• ATMODEON (CAT17_Byte17_bit5)
• SGMODE (CAT17_Byte17_bit0-3)
With ATMODEON, the external input signal is recognized and the external synchronization mode is switched
automatically based on that signal. With SGMODE, the external synchronization mode is switched based on a
value set by the user.
* When ATMODEON is set to 1[h] (ATMODEON=1[h]), the ATMODEON operation is given priority, so the value
set for SGMODE is not updated. To use SGMODE, set ATMODEON to 0[h] (ATMODEON=0[h]).
Auto mode (ATMODEON)
When ATMODEON is set to 1[h] (ATMODEON=1[h]), an external signal is detected. Based on this, the
external synchronization mode is determined and switched automatically. Auto mode is turned ON/OFF using
the following parameter.
Table 12.2-1 ATMODEON Parameter
Parameter
Description
ATMODEON CAT17_Byte17_bit5
0[h] : Auto mode OFF
1[h] : Auto mode ON
Auto mode detection parameter
The parameters (detection flags) in
change when an external signal is input through the
designated pin. Based on this result, the external synchronization mode is switched automatically (see
). In addition, if the parameters set in
are set, then detection will be disabled, even if an
external signal is input to the designated pin.
Table 12.2-2 Detection flag parameters
Input pin
Parameter
Description
S1(46pin)
EXHDET
CAT22_Byte1_bit0
EXT-HD input detection flag
S0(44pin) EXVDET
CAT22_Byte1_bit1
EXT-VD input detection flag
EXVIDEOY(57pin) EXSDET
CAT22_Byte1_bit2
EXT-SYNC input detection flag
EXVIDEO(58pin) EXBDET
CAT22_Byte1_bit3
EXT-BURST input detection flag
* When the designated external signal is input, each parameter is set to “1[h]”. Otherwise, they are set to “0[h]”.
Table 12.2-3 Correspondence between detection flag parameters and external synchronization modes
EXHDET
EXVDET
EXSDET
EXBDET
External
synchronization mode
Controlled parameter
0[h] 0[h] 0[h] 0[h]
INT
SGMODE = 0[h] equivalent
0[h] 1[h] 0[h] 0[h]
LL
SGMODE = 1[h] equivalent
0[h] 0[h] 1[h] 0[h]
VSL
SGMODE = 2[h] equivalent
0[h] 0[h] 1[h] 1[h]
VBSLHP
SGMODE = 3[h] equivalent
1[h] 1[h] 0[h] 0[h]
VRHR
SGMODE = 5[h] equivalent
* Set SGMODE (CAT17_Byte17_bit0-3) to use an external synchronization mode other than the above.
* For information on the controlled parameters,see