52
PSR-S500
■
SYSTEM BOOTING FLOW CHART
Power On
Set the
CPU Registers.
Ports Initialization
FLASH/WE = L
/MKS_IC = L
MKS_ACK = H
/LCD_IC = L
LCD_DISP = L
A/D_SEL = L
/PANEL_IC = L
Other ports = L
Work RAM Initialization
(800mS or longer)
DRAM and SRAM
Initialization
/MKS_IC = H
Access to the
external RAMs.
/MKS_IC: IC101 29pin
OS Starts.
TG IC Initialization and
set the TG IC registers
which are not related to SSP1.
It is OK if the reset
time required 1mS
or longer.
Send the command
to the LCD-C IC.
Change the level from
L to H after the LCD IC
is initialized.
/LCD_IC = H
yes
no
yes
no
LCD Initialization
LCD_DISP = H
The Yamaha logo display
(Opening screen)
Flash ROM check
Clear the Backup
RAM.
ISP1161A1
software resets
300ms Waiting time
Adjust the SSP1
waiting time to over 1.1
seconds from power
switch turned on.
each task
Initialization
PANEL Serial
communications
are started.
Timer is started.
Keyboard data
reception is started.
MKS ACK=L,H
Non-backup parameter
initial setting.
* The communication
to SSP1 is started.
release
the Interruption.
PANEL reset release.
/PANEL IC = H
Start the
PANEL IC access.
After about 7mS,
retrieve the test mode.
Test mode ?
Opening screen
display
Start the PC and
USB connection.
The sound can be
produced by MIDI.
Backup NG ?
Backup parameter
initialization
MAIN Screen
display
Test program
display
Test program
About 6 seconds later,
it can operate the
switches.
Displays the
"backup clear".
Backup parameter
renewal.
Flash ROM is defective
when the "backup clear"
is displayed every time.
The CPU or peripheral devices
(ROM, RAM, Flash ROM) is
defective, if the unit does not
reach this stage.
The LCD or the LCDC IC is
defective, if the LCD does not
display the Yamaha logo.
(opening screen)
Flash ROM
access
Backup parameter
initial setting.
Access to the
ISP1161A1.
The keyboard or
MSK IC is defective, if it
could not enter the test
mode.
The sound can be
produced
by keyboard play.
(The interval is about 6 seconds.)
* SSP1 is not reset by software.
* The SSP1 initial setting time is 1043mS.
DM Circuit board
FLASH/WE:IC101 126pin/127pin
/MKS_IC:
IC101 29pin
MKS_ACK: IC101 37pin
/LCD_IC:
IC101 32pin
LCD_DISP: IC101 31pin
A/D_SEL:
IC101 27pin
/PANEL_IC:IC101 28pin
DM Circuit board
/LCD_IC:IC101 32pin
DM Circuit board
LCD_DISP:IC101 31pin
DM Circuit board
/PANEL_IC: IC101,28pin
DM Circuit board
MKS_ACK: IC101 37pin
DM Circuit board
ISP1161A1(IC501)
