Sdp General Setup; Autodetection Of Sdp Modes - Analog Devices ADV7850 Hardware Manual

per line are output by the SDP.
The ADV7850 uses a VSync and HSync PLL to provide an accurate and reliable lock for both perfect and imperfect video sources.
• VSync PLL: provides extra filtering of the detected VSyncs to give improved vertical lock.
• HSync PLL: designed to filter incoming HSyncs corrupted by noise; providing much improved performance for video signals
with stable time base but poor signal to noise ratio (SNR).
sdp_extend_vs_max_freq
sdp_extend_vs_max_freq, Addr 90 (SDP), Address 0x7B[2]
This control is used to extend the minimum frequency VSync lock range.
Function
sdp_extend_vs_max_fr
eq
1
0 
sdp_extend_vs_min_freq, Addr 90 (SDP), Address 0x7B[1]
This control is used to extend the maximum frequency VSync lock range.
Function
sdp_extend_vs_min_fre
q
1
0 

6.3 SDP GENERAL SETUP

Autodetection of SDP Modes

6.3.1
Automatic standard detection or specific standard forcing on the ADV7850 is achieved by specifying the standards to be automatically
detected. The autodetection registers allows the user to force the digital core into a specific video standard. Setting the relevant bit to 0
inhibits the standard from being detected automatically. For example, to force the standard to PAL only the PAL autodetection bit should
be set. To allow the decoder to detect automatically between PAL, NTSC, and SECAM, the appropriate bits should be set. The results of
the SDP autodetection can be read back via the status registers.
sdp_ad_secam_en, Addr 90 (SDP), Address 0x00[6]
This control is used to enable autodetection of the SECAM standard. Setting this bit to 1 enables the corresponding standard to be
detected. In order to force the part into a particular standard, only the corresponding enable bit for that standard should be enabled. To
allow full autodetection, all standards should be enabled via the respective bit.
Function
sdp_ad_secam_en
1
0 
sdp_ad_n443_en, Addr 90 (SDP), Address 0x00[5]
This control is used to enable autodetection of the NTSC-443 standard. Setting this bit to 1 enables the corresponding standard to be
detected. In order to force the part into a particular standard, only the corresponding enable bit for that standard should be enabled. To
allow full autodetection, all standards should be enabled via the respective bit.
Rev. A May 2012
and sdp_extend_vs_min_freq
Description
Extended minimum frequency VSync lock range
Normal minimum frequency VSync lock range
Description
Extended maximum frequency VSync lock range
Normal maximum frequency VSync lock range
Description
Enable SECAM to be detected
Do not enable SECAM to be detected
can be used to additionally extend VSync lock ranges.
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ADV7850