6-3
5. Data Supply System
(5-2) ARP Register Check
Data write
→
read, and accord check
Error 08: ARP register write, and read data discord
Data 0x00 to 0xFF is written sequentially to the ARP TMAX
register (address 0xC6) and then read for checking.
(5-3) ARP to RAM Data Bus
Data write
→
read, and accord check
Error 09: ARP
←→
RAM data bus error
Data 0x0001 to 0x8000 where one bit each is set to 1 are
written to the address 0 of RAM (IC303) connected to the
ARP (IC301) through the bus, then they are read and
checked. In case of discord, written bit pattern and read
data are displayed. If data where multiple bits are 1 are
read, the bits concerned may touch each other. Further, if
data where certain bit is always 1 or 0 regardless of written
data, the line could be disconnected or shorted.
(5-4) ARP to RAM Address Bus
Data write
→
other address read discord check
Error 10: ARP
←→
RAM address bus error
Caution: Address and data display in case of an error is
different from the display of other diagnosis (de-
scribed later).
Before starting the test, all addresses of RAM (IC303) are
cleared to 0x0000.
First, 0xA55A is written to the address 0x00000, and the
address data are read and checked from addresses 0x00001
to 0x80000 while shifting 1 bit each. Next, the data at that
address is cleared, and it is written to the address 0x00001,
and read and checked in the same manner. This check is
repeated up to the address 0x80000 while shifting the ad-
dress data by 1 bit each.
If data other than 0 is read at the addresses except written
address, an error is given because all addresses were al-
ready cleared to 0. In this check, the error display pattern is
different from that of other diagnosis; read data, written
address, and read address are displayed in this order. How-
ever, the message uses same template, and accordingly ex-
change Address and Data when reading. The following dis-
play, for example,
### Syscon Diagnosis ###
5-4. ARP to RAM Address Bus
Error 10: ARP - RAM Address B
Address
: 0000A55A
Write Data : 00000000
Read Data
: 00080000
Press NEXT Key to Continue
Press PREV Key to Repeat
_
shows the data 0xA55A was read from address 0x00080000
though it was written to the address 0x00000000. This im-
plies that these addresses are in the form of shadow. Also,
if the read data is not 0xA55A, another error will be present.
(5-5) ARP RAM Check
Data write
→
read, and accord check
Error 11: ARP RAM read data discord
The program code data stored in ROM are copied to all
areas of RAM (IC303) connected to the ARP (IC301)
through the bus, then they are read and checked if they ac-
cord. If the detail check was selected initially, the data are
written to all areas and read, then the same test is conducted
once again with the data where all bits are inverted between
1 and 0. If discord is detected, faulty address, written data,
and read data are displayed following the error code 11,
and the test is suspended.
6. AV Decoder
(6-2) 1935 RAM
Data write
→
read, and accord check
Error 14: AVD RAM read data discord
The program code data stored in ROM (IC106 or 107) are
copied to all areas of RAM (IC404, IC405) connected to
the AVD (IC403) through the bus, then they are read and
checked if they accord. Further, the same test is conducted
once again with the data where all bits are inverted between
1 and 0. If discord is detected, faulty address, written data,
and read data are displayed following the error code 14,
and the test is suspended.
During the test, OSD display becomes blank as the OSD
area is also checked.
(6-3) 1935 SP
ROM
→
AVD RAM
→
Video OUT
Error: Not detected.
The data including sub picture streams in ROM (IC106 or
IC107) are transferred to the RAM (IC404, IC405) in AVD
(IC403), and output as video signals from the AVD (IC403).
Though OSD display becomes blank, the output of video
signals continues until the key is pressed.
They are output from all video terminals (Composite, Y/
C, Component) except EURO AV terminal.
