Yamaha DSP-AX1/RX-V1 Service Manual page 32

DSP-AX1/RX-V1
13. DSP RAM CHECK
This menu is used to self-diagnose whether or not the external RAM (IC33, 34, 35) and DSP (IC7, 8)
are connected properly, utilizing the CPU -Ext. RAM interface function included in DSP6.
During signal processing, the status before execution of this menu is maintained.
13.DSP RAM CHECK
#1:NoEr #2:NoEr
• Note that a bus error may be indicated also when there is an error with the terminal other than above
buses.
• Detection for the bus check is executed immediately after resetting.
An error which has occurred after starting DIAG cannot be detected.
14. SUM/VER /PORT
There are four sub-menu items.
Indicates the checksum, version, port of the main microprocessor (IC27 of the function circuit board)
as well as the checksum and version of the sub-microprocessor (IC1 of the DSP circuit board).
The signals are processed in the same way as EFFECT OFF under item 4. PRO LOGIC. (The L/R
signals are output using ANALOG MAIN BYPASS.)
CAUTION : When replacing the microprocessor, be sure to check the microprocessor compatibility
before replacement. The microprocessor may not be suitable for replacement depending on its com-
munication format. Use of a microprocessor whose communication format is not compatible with the
existing one will cause some communication error between microprocessors.
14.SUM/VER/PORT
M:51F5 / S:A3BB
Checksum of sub-microprocessor
(4 figures of alphabets and numbers)
Checksum of main microprocessor
(4 figures of alphabets and numbers)
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#1, #2
Checks the address bus and the data bus of DSP#1 (IC7 of DSP circuit board)
and DSP#2 (IC8 of DSP circuit board), and indicates the connection condition.
"NoEr" appears when no error is detected.
When an error is detected in the data bus;
1619 (example): Indicates that there is an incorrect value between bits 16 and
19. If there are two or more incorrect values, priority is placed on the LSB side.
When an error is detected in the address bus;
Ad01 (example): Indicates that the address bit 1 has an error.
Ad17 (example): Indicates that the address bus bit 17 has an error. (With this
product, however, it is possible that A8 and /OE are short-circuited.)
Checksum of main/sub microprocessor
Checksum: The checksum is obtained by adding 4M bits per 1 octo of the
entire program code and expressing the result as a 4-figure hexadecimal data.
(0xff is added for the area where no code has been entered and for the area
other than ROM code.)