Error Display; General Description Of Checking Method - Sony DVP-S300 Service Manual

6-3. Error Display

In case of an error, the error code and information are displayed as
shown in Figure 7.
Syscon Diagnosis
IF con Ver. 0.620 (9315)
SYScon Ver. 0.400 (62ED)
RAM Check
Error Code: 05
Address : 01001D87
Write Data: 20
Read Data: FF
SIRCS:FF KEY:FF
Figure 7
When the Error Code is other than "05" (write/read data mismatch
error), the Address and Data become "0".
"Diag OK" or "Diag Error End" message blinks, when the check
is all finished or stopped. Press a key here, and the screen returns
to the initial Test Mode Menu screen.

6-4. General Description of Checking Method

This section describes briefly a checking method of each diagno-
sis item, following the order of menu.
The number in ( ) in each item indicates a diagnosis item number.
(2) Memory
(2-2) Syscon ROM (IC803) Check
Checksum calculation
Error: Not detected
At addresses from 0x00000 to 0xfffff of Syscon ROM (IC803),
checksum is calculated by adding 8-bit data, and the result is dis-
played with 4-digit number in hexadecimal notation. As the error
is not detected, compare the displayed result with original ROM
checksum.
(2-3) Syscon RAM (IC802) Check (DMA used)
Syscon ROM (IC803) → Syscon RAM (IC802) matching check
Error 05: Write/read data mismatch error
External RAM (IC802) of IC805 (Syscon) is saved in the stack by
256 bytes each, and ROM data are transferred to the DMA. Then,
the data are compared with ROM (IC803) data every byte. In de-
tail check, the bit inverted data are further written, and rechecked.
During checking, all interruptions are stopped. Also, variables use
only the stacks including save area and bit inverted buffer. As a
processing is executed in the closed circuits within this function,
the data transfer to stack area also uses the DMA. In the detail
check, all areas of external RAM (IC802) are checked twice by
inverting the data, but in the simple check, one block is checked,
then the subsequent 4 blocks are skipped, and also a check of in-
verted data is not executed.
If write/read mismatch error occurred, checking can be repeated.
→Check item name
→Error code
→Address where error occurred
→Written data (2 – 8 digits)
→Read data (2 – 8 digits)
(3) Destination Setting
(3-2) Destination setting Check
I/O port read
Error: Not detected
The destination setting port (I/O) is read, and displayed with hex.
number.
Error is not detected.
(4) Gate Array (62000CFh: Peripheral Access Control)
(4-2) Register
Write data → Read data matching check
Error 05: Write/read data mismatch error
Register at adrs=62000CFh (Peripheral Access Control)
Whether written data and read data are matched is checked.
If write/read mismatch error occurred, checking can be repeated.
(4-3) Reset Line
Write → Hard reset → Read
Error 02: Reset error
0xff is written to the register (Peripheral Access Control) at
adrs=62000CFh, and whether it is initialized to "0x00" by the re-
set pulse is checked.
(5) Drive
(5-2) EEPROM (serial) (IC801)
Data write → Read matching check
Error 05: Write/read data mismatch error
11: Serial transfer error
12: EEPROM not ready
16-bit data is written to the address 0 of EEPROM (IC801), and it
is read to check for matching. Before checking, the content of ad-
dress 0 is read for saving, but if it cannot be read, the error is
displayed and operation is terminated, and data writing is not ex-
ecuted.
In this diagnosis, 16-bit data is checked. 16 kinds of patterns are
written by shifting 1 bit each from 0x0001 toward the left.
If write/read mismatch error occurred, checking can be repeated.
Even if an error occurs after write/read check started, the saved
data are written when this diagnosis is quitted, but whether data
are written correctly is not guaranteed.
(5-3) SSI (Serial)
Serial register write → Register read matching check
Error 05: Write/read data mismatch error
33: SSI serial transfer error
0x00 – 0xff data are written to the FCCR register for SSI, then
they are read to check for matching.
If write/read mismatch error occurred, checking can be repeated.
6-2