Circuit Description Of The Respective Boards; Overall Function Of Ma-97 Board - Sony PCS-1500 Service Manual

3-2. Circuit Description of the Respective Boards

3-2. Circuit Description of the Respective Boards

3-2-1. Overall Function of MA-97 Board

The MA-97 board has the functions of all operations of the PCS-1500/1500P system except for receiving
and demodulation of the infrared video signal (AV-Link), receiving of the SIRCS signal from the remote
commander, the optional BRI 4B and the V.35 interface. Most of the external input/output connectors are
attached to the MA-97 board directly. The block diagram of the MA-97 board is shown in Fig. 3-3.
Dividing the MA-97 board into functional blocks
The MA-97 board circuit can be divided into the following functional blocks. (Refer to Fig. 3-4.)
PWR block :
The PWR block consists of the DC-DC step-down converters, voltage regulators and LED illuminat-
ing/flashing circuit. It generates the various voltages that are required in the PCS-1500/1500P from
the DC 12V power and controls on/off of these powers. (Refer to Fig. 3-4 6.)
CPU block :
The CPU block consists of the CPU, flash memories, SDRAMs, bus control circuit, buffers and
debugging port line driver/receiver. It controls the entire circuit of the PCS-1500/1500P system.
(Refer to Fig. 3-4 1.)
PCMCIA block :
The PCMCIA block consists of the PCMCIA interface buffers and power supply control IC. The
PCMCIA block is the interface for the memory card. (Refer to Fig. 3-4 2.)
UART block :
The UART block consists of the universal asynchronous receiver & transmitters, and the line driver/
receivers. The UART block is the VISCA interface for the camera (PCS-C150/C150P) and the
interface for the T.120 port. (Refer to Fig. 3-4 7.)
SIRCS block :
The SIRCS block consists of microcontroller for the decoding/encoding SIRCS signal. It decodes the
SIRCS signal that is supplied from the remote commander via the RX-47 board, and encodes/outputs
the monitor control SIRCS signal that is to be output to the IR repeater terminal. (Refer to Fig. 3-4
3.)
BRI block :
The BRI block consists of the I-Interface control IC, SRAMs and transformers for ISDN BRI lines.
It performs transmission and receiving the BRI-2B line data and the call control.
(Refer to Fig. 3-4 5.)
NETIF block :
The NETIF block consists of the data alignning IC and buffers. It aligns the serial data between the
optional board and the VCP block. It also performs switching of the interfaces in accordance with the
optional board in use. (Refer to Fig. 3-4 4.)
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PCS-1500/1500P