Sony DVP-K800D Service Manual page 77

(8) Video consumer related items
(8-2) 1914 (serial)
Color bar output from NTSC encoder. (Color bar enable command)
Error 11: Serial transfer error
The test is set to start up the serial communication to NTSC encoder with the V sync interrupt so that the color bar enable command is
transferred to 1914. The V sync interrupt and the internal serial 1 interrupt are used. When error is not detected, a message is output
which prompts key input. Check the color bar output.
(8-3) 1914 Read
ID read→Agreement check with the default value.
Error 40: 1914 ID error
The device ID of 1914 is read. Error is issued when the read-out value is not "1914 (hex)".
(8-4) 1914 Vertical sync
Measure the 1914 V Sync interrupt cycle with CPU.
Error 41: V sync interrupt is not detected.
42: V sync interrupt cycle error
Number of interrupt of every 200 ms is counted. If number of interrupt is in the range of 11 to 13, it is judged OK. It must be exactly
12, but error within the range of ±1 is allowed.
(8-5) Still picture output (Direct write into DRAM)
Pattern data→AVD→Video Out
Error 31: AV decoder interrupt (DMA transfer) is not detected.
This test is performed as follows. The pattern is written directly to the SDRAM of AV decoder and checks the picture display. Firstly,
pattern data equivalent to one screen is written while changing the luminance signal data every pixel. The color difference signals of Cr
and Cb are set to 80h which is B/W signal, and turn the display to on. Then the color difference signals are written while changing data
every line. Because both of luminance and color difference signals are the regular pattern, the processing speed is increased by transferring
the repetition data by DMA. When the detailed check mode is selected, the color difference signals that are written in the areas outside
display area, are copied by the DMA transfer and the display colors are changed one after another. When error is not detected, a message
is output which prompts key input. Check the pattern output.
(8-6) Still picture output (Through ARP)
ROM picture data→ARP→AVD→Video Out
Error 10: Data transfer error between chips
ROM data is transferred to AV decoder through ARP and the display picture is checked. When error is not detected, a message is output
which prompts key input. The output picture is same as the startup picture.
(8-7) DNR (serial)
ROM picture data→ARP→AVD→DNR→Video Out (Outline)
Error 10: Data transfer error between chips
The picture is checked by transferring the special command of diagnostics to the output still picture. When error is not detected, a
message is output which prompts key input. This check is performed in the machines in which DNR is installed. Output picture that is
the same as (8-6) Still picture output is used. When DNR works effectively, color changes significantly.
In the models in which DNR is not installed, error code 0 is returned.
5-10