Psr-S950 System Booting Flowchart - Yamaha PSR-S750 Service Manual

PSR-S950 SYSTEM BOOTING FLOWCHART

Power ON
Setting CPU registers.
Initializing SDRAM for
BOOT, 0 clearing, setting
constant.
Initializing SH7731 port.
PSWO = H (IC26, 4)
/USB-RES =L (IC13, 18)
/SWP-IC = L (IC13, 17)
/RGB-RES = L (IC13, 16)
/DAC-IC = L (IC13, 14)
MIDI-IC = H (IC13, 13)
/NAF-WP = L (IC202, 19)
/CPU-MUTE = L (IC17, 1)
/CPU-SPOFF = L (IC17, 9)
/DA-MUTE = L (IC5, 1)
BL-ON/OFF = L (IC1, D12)
Initializing EBUS driver.
/SWP-IC = H
(EBUS Start)
EICN = H (IC603, 1)
Keyboard and
switch status taken in.
/SWP-IC = L
EICN = L
Yes
Installation mode?
(Start SW)
No
Normal
starting
Opening screen displayed.
BL-ON/OFF = H
Port initial setting
/RGB-RES = H
/USB-RES =H
Port initial setting
/SWP-IC = H
No
Mounting internal drive
should be succeeded.
Error! Internal drive is
Yes
If accessing Program Flash
doesn't start, SH7731 (IC1)
may be faulty.
Accessing Program
Flash (IC16) starts.
If accessing SDRAM doesn't
start, SH7731 (IC1) may be faulty.
Accessing SDRAM
(IC204, 205, 206, 207)
starts.
Communication with
EBUS starts.
Installation screen
displayed.
BL-ON/OFF = H
END
Installation
by user
Internal drive not
formatted or
connected.
Install.
unformatted.
END
No
Main program
should exist.
Yes
Main program not found!
Animation starts.
Main program read from
NAND (IC202).
No
Has main program
been read successfully?
Yes
Media Error!
If failed to reach here, possible cause
may be in;
Initializing SH7731 port.
PSWO = H
/USB-RES =L
/SWP-IC = L
/RGB-RES = L
/DAC-IC = L
MIDI-IC = H
/NAF-WP = L
/CPU-MUTE = L
/CPU-SPOFF = L
/DA-MUTE = L
BL-ON/OFF = H
SSP2 internal resetting.
Opening screen displayed.
Canceling SSP2
internal resetting.
BL-ON/OFF = H
Resetting negation.
/USB-RES =H
/SWP-IC = H
/RGB-RES = H
/DAC-IC = H
MIDI-IC = L
/NAF-WP = H
Initializing EBUS driver.
(EBUS Start)
EICN = H
Backup Flash transferred
ROM SDRAM
(IC23)
SSP2 PSWO = L
(IC26, 1)
PSR-S750/PSR-S950
Internal drive is
END
faulty.
END
No main program.
A
73