Analog Devices Advantiv ADV7611 Hardware User's Manual page 134

UG-180
CP HDMI CONTROLS
HDMI_CP_LOCK_THRESHOLD[1:0] , Addr 44 (CP), Address 0xCB[1:0]
Locking time of filter used for buffering of timing parameters in HDMI mode.
Function
HDMI_CP_LOCK_THRESHOLD[1:0]
00 (default)
01
10
11
FREE RUN MODE
Free run mode provides the user with a stable clock and predictable data if the input signal cannot be decoded, for example, if input video
is not present. It controls default color insertion and causes the ADV7611 to generate a default clock. The state in which this happens
can be monitored via the CP_FREE_RUN
configured automatically for HDMI modes.
Free Run Mode Thresholds
The free run threshold parameters define the horizontal and vertical conditions under which free run mode is entered. The horizontal
and vertical parameters of the incoming video signal are measured and compared with internally stored parameters, and the magnitude of
the difference decides whether to enter free run. The internally stored parameters are decoded by default from
VID_STD[5:0]. For video standards other than the preprogrammed settings of
can be set manually.
Horizontal Conditions
In the case of the horizontal conditions, the length of the incoming video line is measured based on the 28.6363 MHz crystal clock. This
value is compared with the internally stored horizontal parameter, the ideal line length. The CH1_F_RUN_TH[2:0] control bits allow the
user to select the threshold for Channel 1. The ideal line length can be manually set via the Free-run Line Length control,
CH1_FR_LL[10:0].
CH1_F_RUN_THR[2:0] , Addr 44 (CP), Address 0xF3[2:0]
Free run threshold select for Sync Channel 1. Determines the horizontal conditions under which free run mode is entered or left. The
length of the incoming video line is measured based on the crystal clock and compared to an internally stored parameter. The magnitude
of the difference decides whether or not sync Channel 1 enters free run mode.
Function
CH1_F_RUN_THR[2:0] Description
000 Minimum difference to switch into free run is 2. Maximum difference to switch out of free run is 1.
001 Minimum difference to switch into free run is 256. Maximum difference to switch out of free run is 200.
010 Minimum difference to switch into free run is 128. Maximum difference to switch out of free run is 112.
011 Minimum difference to switch into free run is 64. Maximum difference to switch out of free run is 48.
100 (default) Minimum difference to switch into free run is 32. Maximum difference to switch out of free run is 24.
101 Minimum difference to switch into free run is 16. Maximum difference to switch out of free run is 12.
110 Minimum difference to switch into free run is 8. Maximum difference to switch out of free run is 6.
111 Minimum difference to switch into free run is 4. Maximum difference to switch out of free run is 3.
Description
Slowest locking time
Medium locking time
Fastest locking time
Fixed step size of 0.5 pixels
status bit. (Refer to the CP Status section for more information.). The free run feature is not
Rev. A | Page 134 of 184
Hardware User Guide
PRIM_MODE[3:0] and VID_STD[5:0], the parameters
PRIM_MODE[3:0] and