Sony DVP-S715 Service Manual page 60

(5-4) Servo DSP Download
DSP (IC506) code area ROM/RAM discrimination
RAM: Program download → Revision data read
ROM: Revision data read
Error 04: Data read error
13: DSP data not ready
For the Mask ROM, no download can be executed. Download is
possible for the RAM only. ROM/RAM is discriminated by the
DBUSY signal of DSP (IC506) pin 4 after hardware reset. The
diagnosis provides exclusive download flag.
For this flag, download not executed
download already executed : 1
download error
ROM/RAM is discriminated by the status of DBUSY signal after
hardware reset. If RAM, the servo control code is downloaded.
If no error is found, the version No. is read from address:200, and
displayed.
If ROM, the version No. is read from address:200 immediately.
Compare displayed data with existing data.
If RAM, "DSP Download Rev.=xxxx" is displayed.
If ROM, "DSP Mask ROM Rev.=xxxx" is displayed.
(5-5) Servo DSP Register
(Program download) → Data write → Read matching check
Error 04: Data read error
05: Write/read data mismatch error
13: DSP data not ready
14: DSP download error
The download flag is checked, and if 0, the program is downloaded.
However, in the case of ROM, it is not downloaded.
Unless download error occurs, the content of address 200h of DSP
(IC506) is read for saving, then checking starts. In this check, 16
kinds of patterns are written to the address 200h by shifting 1 bit
each from 0x0001 toward the left, then they are read.
If write/read mismatch error occurred, checking can be repeated.
(5-6) Servo DSP Reset Line
Register write → Hard reset → Register read
Error 02: Reset error
13: DSP data not ready
14: DSP download error
In the case of RAM, this diagnosis checks that the register cannot
be read after hardware reset. Unless download error occurs, the
content of address 200h of DSP (IC506) is read, and after hard-
ware reset, the data is read again for comparison.
The check results in OK, if the register cannot be read, or data are
not matched even if it can be read. The reset error occurs if read
data are same as that before hardware reset.
In the case of ROM, whether the version No. is initialized by the
reset is checked. First, the version No. is read, then its comple-
ment is written.
After hardware reset, the data is read again and if it matches the
written data, the reset error occurs.
: 0
: 2
6-3
(6) Data Source
(6-2) Register in ARP (IC806)
Register write → Register read matching check
Error 05: Write/read data mismatch error
Data from "0x00" up to "0xff" are written to 12 registers where all
bits can be written and read, then read to check for matching.
If write/read mismatch error occurred, checking can be repeated.
(6-3) Reset Line in ARP (IC806)
Register write → Hard reset → Register read
Error 02: Reset error
05: Write/read data mismatch error
After "0xfe" is written to the INTEN3 register, whether it is ini-
tialized to "0x00" by the reset pulse signal is checked.
To make sure, the written data is read to check for matching be-
fore reset is executed.
(6-4) DRAM (IC810) in ARP
ROM data → ARP (IC806) → DRAM (IC810) → ARP (IC806)
read matching check
Error 03: Data write error (ARP (IC806) is not enabled for data
writing)
04: Data read error (ARP (IC806) is not enabled for data
reading)
05: Write/read data mismatch error
ROM (IC803) patterns are copied to all areas to be checked. Each
time 256 bytes are copied, the addresses of copy source (ROM)
are returned by 254 bytes. In detail check, all areas are checked to
verify all bits in DRAM (IC810), then the inverted data are further
checked in the same manner. The bus width of ARP (IC806) is 16
bits. This check program displays addresses in 16 bits.
Overwriting by the shadow can be detected, as the data are written
to all areas, then read. In the detail check, all areas of RAM (IC802)
are checked twice by inverting the data, while in the simple check
one block is checked, then subsequent 4 blocks are skipped, and
also inverted data are not checked.
If write/read mismatch error occurred, checking can be repeated.
(6-5) Interrupt Line in ARP (IC806)
Data transfer request → Data transfer stop interruption from ARP
(IC806)
Error 21: ARP (IC806) interruption is not detected
AC-3 audio data stored in ROM (IC803) are transferred to the
ARP (IC806), then the designated sector data output stop inter-
ruption from ARP (IC806) is detected.
To discriminate the Decrypt (IC811) interruption which is also
sent in the same line, the Decrypt (IC811) interruption is all masked.