Sony UP-D70XR, Руководство по обслуживанию

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4-4
UP-D70XR
c) Transmission control between each board
Serial communication between each board (SY-270 board
⇔
other board) is performed by time
division mutual toward one system.
Sequence of this timing division is performed as follows. Baud rate is 31250 bps.
.
When receiving (Child data
⇒
SY-270 board)
1) Before data sending, child
board sets nARB to L.
2) SY-270 board ensures
nARB to L, SY-270 board
stops rotation of nSEL and
lowers nRTS.
3) Child board sends the data
1byte.
4) SY-270 board rises RTS,
child rises nARB.
5) When nARB is risen, SY-
270 board performs rotation
again.
.
When transmitting (SY-270 board data
⇒
Child)
1) SY-270 board stops rotation
by child which want to send
nSEL.
2) SY-270 board sends 1byte
data.
3) Child board rises RTS. CTS
is risen by beating clock of
IC307 (D,FF) on SY-270
board.
4) SY-270 board ensures CTS
was risen, and clears CTS
again to perform rotation
again.