Psr-S770 System Booting Flowchart - Yamaha PSR-S770 Service Manual

■ ■ PSR-S770■SYSTEM■BOOTING■FLOWCHART
Power ON
Setting CPU registers.
Initializing SDRAM for BOOT,
0 clearing,
setting constant.
Initializing SH7731 port.
BL-ON = L (CN401, 3)
BL-PWM =L (CN401, 4)
BL_POW_EN = L (IC412, 4)
PSWO = H (IC013, 2)
/DA-MUTE = L (IC005, 13)
/PRG-WP = L (IC008, 16)
/BACKUP-WP = L (IC010, 16)
/CPU-MUTE = L (IC009, 1)
/CPU-SP-OFF = L (IC009, 9)
/USB-IC = L (IC012, 18)
/SWP-IC = L (IC012, 17)
/DAC-IC = L (IC012, 14)
MIDI-IC = H (IC012, 13)
Initializing EBUS driver.
/SWP-IC = H
(EBUS Start)
EICN = H (IC016, 1)
Keyboard and
switch status taken in.
/SWP-IC = L
EICN = L
Yes
Installation mode?
(Start SW)
No
Normal
starting
If accessing Program Flash
doesn't start, SH7731
(IC001) may be faulty.
Accessing Program
Flash (IC008) starts.
If accessing SDRAM doesn't
start, SH7731 (IC001) may be
faulty.
Accessing SDRAM
(IC206, 208) starts.
Communication with
EBUS starts.
Installation screen
displayed.
BL-ON = H
BL_POW_EN = H
BL-PWM = H
END
Installation
by user
Initializing SH7731 port.
BL-ON = L (CN401, 3)
BL-PWM =L (CN401, 4)
BL_POW_EN = L (IC412, 4)
PSWO = H (IC013, 2)
/DA-MUTE = L (IC005, 13)
/PRG-WP = L (IC008, 16)
/BACKUP-WP = L (IC010, 16)
/CPU-MUTE = L (IC009, 1)
/CPU-SP-OFF = L (IC009, 9)
/USB-IC = L (IC012, 18)
/SWP-IC = L (IC012, 17)
/DAC-IC = L (IC012, 14)
MIDI-IC = H (IC012, 13)
If failed to reach here, possible cause
may be in;
• SDRAM
Opening screen displayed.
(Tuning fork mark)
BL-ON = H
BL_POW_EN = H
BL-PWM = H
Resetting negation.
/SWP-IC =H
/USB-IC = H
MIDI-IC = L
/DAC-IC = H
DA-MUTE = L (IC005, 12)
Initializing EBUS driver.
(EBUS Start)
EICN = H
Yes
Test mode?
ERR-DETECT pulse output
No
Test mode displayed.
PSR-S770/PSR-S970
(IC006,1)
END
A
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