Sony BVH-2000, Operation And Maintenance Manual

Page: 308 / 505

5-6-3. Outline of SY-80 Board
This board converts the control commands supplied from the
SY-79 board control and controls the
timing signals which are output from the LG board. Moreover,
transfers the status data control data to and from
code generator/ reader and the servo system.
The commands from the SY-79 board are read into the CPU
through the SY-80 board common memory. The common
memory is composed of 1 RAM, it can handle data
reading and writing from the CPUs of both the SY-79 and SY-80
boards, and data are transferred
to and from the CPUs
out one end the data written the other end.
1.
CPU
The CPU (Central Processing Unit) is operated by the
2.4576 clock in accordance with the program
written into the 12K-byte ROM. As with the SY-79 board, major
ontrol
VTR out
each field and control. which involves a leeway in terms of time.
in
handling (steady level handling).
is the first CTC,
CPU is interrupted field by field, as with the SY-79 board, and
system control program.
The dial
are the
counts them, as with the SY-79 board. The pulses are counted in
the SHUTTLE mode
the SY-79 board and
by the SY-80 board.
The third and fourth channel CTCs count the
when the
timer roller is rotating in the forward or reverse direction.
SY-80BOARD BLOCK DIAGRAM
IC4H
3. ROMs
Written into these SY-80 board ROMs are the 12K-byte
ROM a
capacity of 4K-byte, and the ROMs are accessed by the
IC IF: OOOOH - OFFFH
ICID: IOOOH- IFFFH
IC IC: 2000H - 2FFFH
4. RAM
The RAM transfers the data to and from the CPU on the SY-80
board.It has a
and it is accessed the 8000H-
87FFH addresses with the address decoder IC2E.
5.
z
o
I-
<l
a:
w
Q..
o
rcu
is
communication between the respective CPUs on the SY-79 and
The capacity of the ICl J is 2K-byte. Half this capacity, or 1K-
it
AOOOHto A3 FFH addresses while the remaining capacity. or 1K-
>-
a:
o
w
I
I-
to A 7FFH addresses.
connectors are converted into command data on the SY-79
which have been written by the SY-80 board are read out and
h ...... rf"r ....• ~a
is controttcd,
by the SY-80 board, the data thus written are read out by the SY-
79 various
checked
(FROM CONTROL PANEL)
(FROM
,...----_1-
TIMER PULSE (FROM RL)
TAPE DIRECTlC~ (FROM RU
DATA ADDRESS
,........::.~_.J.....L ~ __
--L..J...,,--,.~---,,--,~ilL-_-J....J.
~~----l'--L.- ~ __
.L..L...---"-'\. TO/FROM
L.-.._-..,...-r--~------r-~~-~~--,..,.----, ...------........,..------,
,.------.,--r---v
LG/SVI TC
TO
.---------1 1-----.,/ LG/SV I TC
BVH-2180(U/C)/PS/PM