Sony DVP-K800D Service Manual page 81

(10) AC-3 related items
(10-2) AC-3 decoder register
Write into serial register→Read from register and check if data agree
Error 05: Write data and read data do not agree.
11: Cannot receive serial data.
55: AC3 decoder (DSP) serial transmission interrupt is not detected.
This test is performed by writing a 20-bit data to the address 02F61h of the AC-3 decoder (DSP) and read it to check that the write data
and the read data agree. Data from 0x00001 to 0x80000 is shifted to the right by one bit, and test repeated 20 times repeatedly.
(10-3) AC-3 decoder Reset line
Write into register→Resetting hardware→Read from register
Error 02: Reset error
11: Cannot receive serial data.
55: AC3 decoder (DSP) serial transmission interrupt is not detected.
This test is performed by writing the 20-bit data 0x34567 into the AC-3 decoder (DSP) address 02F61h, firstly then hardware reset is
executed. Then the data is read and confirm that the data is initialized to 0x00000.
(10-4) AC-3 decoder download (serial)
Test program downloading operation check
Error 05: Downloading program does not work.
11: Cannot receive serial data.
14: Cannot download program.
55: AC3 decoder serial transfer interrupt is not detected.
This test is to check if the diagnosis test program works correctly or not. This test is performed by downloading the test program. The
test program "abcde" is written to the AC-3 decoder address 0478d. Check that the data which has already been written to the address
0478d from host, is re-written to "abcde" when the diagnosis program is downloaded. The machine is set to the "test tone input mode"
in order to download the test program. However, the test tone is not output because mute is applied. When write data and read data do
not agree, error code 05 is output.
(10-5) AC-3 decoder SRAM check
AC-3 decoder SRAM is check by the decoder itself.
Error 03: Command write error
11: Cannot receive serial data.
14: Cannot download program.
55: AC3 decoder serial transfer interrupt is not detected.
57: Data bus error between AC3 decoder and SRAM
58: Address bus error between AC3 decoder and SRAM
93: Test is interrupted by the limit time over (about 1 second).
This test is performed by downloading the SRAM check program to the AC3 decoder, let the program operates and result is returned.
The following two points are check.
(1) Data check: "00", "55", "AA" and "FF" are written/read to and from address 7100h.
(2) Address check: 7FFE byte data is written sequentially to the address starting from "FF", "55", "00", "FF", "55" and "00"..., then the
data is read and checked. Result of check is read out from the decoder register. If end of check signal is not returned within one
second, time-over error is issued.
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