Sony BVH-2000, Operation And Maintenance Manual

Page: 306 / 505

5-6. SYSTEM CONTROL SYSTEM
5-6-1 Outline of
The circuitry of the system control system is composed of the
three circuit boards (SY-79, SY-80 and LG-02) in the card rack
and the two circuit boards
and DY) inside the optional
function control called
BKH-2011/2012/2013.
There are three kinds of control panels: Type I (BKH-2011),
Type II (BKH-2012) and III (BKH-2013). By replacing the
control it is to use the
VTR
system at different
levels.
CARD RACK BLOCK
SY-79 Board:
A CPU is mounted on this board. It generates
the commands for the
external equipment which is connected to the
control and remote connectors, decoding
the statuses and for corttrolling the VTR
hardware.
SY-80 Board: A CPU is mounted on this board. While
information between the servo
system and optional time code reader/generator
(BKH-2015A: TC-14A it controls the
audio and video
signals which are output from the LG-02 board
in accordance
with the commands supplied
from the SY-79 board.
LG-02 Board: This outputs the
to the command
from the SY-80 board,
to the various boards. Some of the output
are output after having been synchronized
with the sync
DY Board:
This the data indicating the settings of
the switches on the control panel to the SY-79
board and, in accordance with the data from
SY-79 board, it controls the ngntmz/extmauistnnz
of the LEOs inside the switches.
This generates the signals which indicate the
SEARCH dial's rotational and direction,
and it outputs the signals to the SY-79 and SY-
80 boards. Furthermore, it displays the characters,
which correspond
to the display data supplied
from the SY-79 board, on the fluorescent
SYSTEM CONTROL BLOCK DIAGRAM
BVH-2000( U/C) IPS/PM
BVH-2180(U/C)/PS/PM
Board
This board generates the VTR control
signals from the equipment which has been connected to the
remote connectors and control panel. and it writes these signals
board. addition.
remote connectors.
1 CPU
The CPU (Central Processing Unit) is operated by the
2.4576 MHz clock signal in accordance with the program
the the is
carried out with each field
control which involves a leeway in terms of time. is carried out
in the programmed
sequence by non-interruption handling
connected to
¢:
This is the CPU clock input signal. It is generated by
MHz
to 2.4576 MHz and its waveform. It is
as the clock signal of the CPU.
RESET: The CPU is reset by the following two commands:
When switch S3 on the SY-80
• When the power is switched on and the POWER
ON RESET pulse is supplied.
WAIT: The ceases to operate while the """SY WAIT'
from
common memory ICll 1K RAM) on the SY-80 board
has already been accessed by the CPU on the SY-80,
the """"SY WAIT' signal is input in cases where an
has the memory
from the SY-79 CPU.
INT (INTERRUPT):
NMI (NON-MASKABLE INTERRUPT):
There are two CPU
INT and
INT be
enabled or disabled by the software program; NMI
denotes interruption which cannot be disabled by the
software program.
RD (READ OUT):
The software program relating to cases where WRITE
or READ is output contains
commands for the I/O
port and commands memory.
MREQ (MEMORY REQUEST):
When a WRITE is requested to the memory, both the
WR and MREQ become active.
5-6-1
SYSTEM CONTROL SYSTEM
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