Sequnce After The Power On - Pioneer XC-IS21T Service Manual

7.2.2 SEQUNCE AFTER THE POWER ON

Note 1 : IC No. or P∗∗ without name indicate the pin No.
of microcomputer.
Standby states
POWER ON
Power is ON.
Transmit the bus data.
Initialize the LCD microcomputer.
DECK control IC starts
the data transfer.
Does CD door open ?
Is P9 and P10 at "H" level ?
Close the CD door.
Initialize the DECK.
Perform the following process after
one second after the POWER ON.
Transfer the Function, Volume, BASS
and TREBLE data to the volume IC. (∗3)
Function : CD (∗4)
Initial setting of CD decoder IC.
P22 CDCONT : "L"
Perform the following process after
3.9 seconds after the POWER ON.
Release the system MUTE.
P71 SYSMUTE : "H"
Perform the following process after
4.0 seconds after the POWER ON.
Release the speaker relay.
P70 SPCONT : "H"
P35 SYSPOWER : "H"
System bus communication (∗1)
Transfer the system POWER ON.
P4 LCD POWER ON : "H"
P53 LCDRST : "L" RESET
Starts the LCD communication (∗2)
P28 VOLDATA
Microcomputer P34 VOLCLK
P75 EXPCE
No
Yes P11 : "H"
Function : TUNER (∗5)
Initialize the TUNER PLL IC.
P64 TXPOW : "H"
The condition that MUTE
is not released.
• VOLUME : 0
• DECK Function : excepting PLAY
Note ;
∗1 : System bus communication
∗2 : Starts the LCD communication
∗3 : Transfer the Function, Volume, BASS
and TREBLE data to the volume IC.
∗4 : Initial setting of CD decoder IC
∗5 : Initialize the TUNER PLL IC
Transfer
DECK Initialize Sequence
MOTOR ON
Does the DECK Head down ?
(Is the MODE SW OFF ?)
No
Is three times ?
No
500 msec.
solenoid is ON ?
MOTOR OFF
XC-IS21T
P29 SYSCLK
P46 SYSDATA
P47 SYSREQ
P48 LCDCLK
P49 LCDCE
P50 LCDDATA
P27 VOLCE
P28 VOLDATA
P34 VOLCLK
P17 CDCLK
P18 CDLAT
P19 CDDATA
P65 TXCE
P66 TXODAT
P67 TXCLK
P68 TXIDAT
Check P79 MODE SW
input is "L".
Yes
Yes
Retry it to two times.
IC2601(BU4094) P12 is "H"
IC2601(BU4094) P11 is "L"
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