Analog Devices ADV8005, Справочник по аппаратуре

Страница: 111 / 317

ADV8005 Hardware Reference Manual UG-707
When crop or album mode is enabled, frame latency will be different from what is listed in Table 21 . In this case, the user can use the following
methods to measure frame latency:
pvsp_rb_frame_latency[2:0] and
pvsp_rb_hsync_latency[11: 0] are read only registers. Their values are real-time frame and HSync latency between input and output video.
Frame latency may vary within a range; the
pvsp_rb_max_latency[14:0] readback register indicates the maximum frame latency, while
pvsp_rb_min_latency[14:0] indicates the minimum frame latency. If pvsp_frc_latency_measure_en is set to 0, pvsp_rb_max_latency[14:0] and
pvsp_rb_min_latency[14:0] are cleared.
If asserting
pvsp_frc_latency_measure_en , the PVSP will monitor the values in pvsp_rb_frame_latency[2:0] and
pvsp_rb_hsync_latency[11: 0] , then record their maximum and minimum values in pvsp_rb_max_latency[14:0] and
pvsp_rb_min_latency[14:0] . Both of these signals are 15 bits wide – the highest 3 bits are the frame latency and the lowest 12 bits are the HSync
latency. Note that it will take several seconds for PVSP to find the maximum and minimum frame/HSync latency.
In a normal case (not game mode), the PVSP’s input video and output video latency are consistent.
pvsp_frc_latency_measure_en , Primary VSP Map, Address 0xE8F0[6]
This bit is used to enable frame latency measuring. The results are recorded in pvsp_rb_max_latency and pvsp_rb_min_latency.
Function
pvsp_frc_latency_measure_e
n
Description
0 (default) Disable frame latency measuring
1 Enable frame latency measuring
pvsp_rb_frame_latency[2:0] , Primary VSP Map,
Address 0xE870[6:4] (Read Only)
This signal is used to indicate the real time vsync latency.
Function
pvsp_rb_frame_latency[2:0] Description
0xXXX number of frame latency
pvsp_rb_hsync_latency[11:0] , Primary VSP Map, Address 0xE875[7:0]; Address 0xE876[7:4] (Read Only)
This signal is used to indicate the real time Hsync latency.
Function
pvsp_rb_hsync_latency[11:0] Description
0xXXX number of hsync latency
pvsp_rb_max_latency[14:0] , Primary VSP Map, Address 0xE8F2[7:0]; Address 0xE8F3[7:1] (Read Only)
This signal is used to record the maximum frame latency.
Function
pvsp_rb_max_latency[14:0] Description
0xXXX Maximum of frame latency
pvsp_rb_min_latency[14:0]
, Primary VSP Map, Address 0xE8F4[7:0]; Address 0xE8F5[7:1] (Read Only)
This is signal is used to record the minimum frame latency.
Function
pvsp_rb_min_latency[14:0] Description
0xXXX Minimum of frame latency
3.2.1.6. Game Mode
Frame latency should be as small as possible for gaming applications. PVSP supports a game mode, which has nearly zero frame latency (latency
less than 5 lines).
To enable the game mode of PVSP,
pvsp_bypass_ddr_mode should be asserted.
Rev. A | Page 111 of 317