Rotel RDV-1092 Service manual

Serial Interface Design Specification Issued by: Videon Central, Inc.
Revision: <1.22> 2005/05/19

Serial Interface Design Specification

1. Objectives

This document will describe the serial interface protocol that is used by an external controller
to communicate with the decoder board, which is based upon the CS98200 and was created
by Videon Central, Inc.

2. Scope

This document will provide the information necessary to thoroughly understand the design of
the serial interface protocol. The detail provided and the references made in this document
will be sufficient enough for an engineer to implement and build upon the serial interface
protocol.

3. References

Document File ID Document Title

4. Product or System Description

The decoder board supports DVD Video, DVD Audio, CD, and MP3 playback as well as
audio pass through and video pass through. It is intended to operate as a slave to an external
controller board from which it accepts all commands and to which it sends system status
information and miscellaneous requests.

5. Serial Protocol

The UART module of the CS98200 provides an RS-232 serial interface and is the basis of the
protocol that is used for communication between the decoder board and an external controller
board. This module is configured in the following manner:

1.) Baud Rate: 19200

2.) Data Bits: 8

3.) Stop Bits: 1

4.) Parity: None

5.) Delay Between Transmitted Data Bytes: None

Messages that are passed from the external controller board to the decoder board are referred
to “commands” and messages that are passed from the decoder board to the external
controller are referred to as “status” or “requests”.

Since it is intended to operate as a slave, the decoder board receives all user and mode change
commands from the external controller board. Settings that are local to the decoder board are

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Serial Interface Design Specification Issued by: Videon Central, Inc.
Revision: <1.22> 2005/05/19

stored in non-volatile memory during power down while all external settings are stored in
non-volatile memory on the external controller board. These external settings are sent to the
decoder board by the external controller board upon power up via an initialize command.

5.1 Message Structure

The serial protocol is based upon variable length messages of the following structure:
Byte 0 Byte 1 Byte 2 Byte 3 Bytes 4 to

Byte (N – 1)

(N – 2)

Sync Byte Count ID Opcode Data Check Sum

5.1.1 Sync Byte

The sync byte indicates the beginning of a new serial message and always contains a
value of 0xFE. If 0xFE is found anywhere else in the serial message, an educated
decision must be made by the module receiving the message to interpret it as the start
of a new message or as data within the current message.

5.1.2 Count

The count byte indicates the number of bytes in the serial message from the ID byte
through the end of the data bytes.

5.1.3 ID

The ID byte indicates the source of the serial message. If this byte contains a 0x01,
then the decoder board sent the message. If this byte contains a 0x02, then the
external controller sent the message. A value of 0x00 within this byte is reserved.

5.1.4 Opcode

The opcode byte indicates the operation to be performed. A list of the possible
opcode values and associated operations may be found in the sections below.

5.1.5 Data

The data bytes contain any and all information required to carry out the operation
indicated by the opcode.

5.1.6 Check Sum

The check sum byte is the sum of the count byte, the ID byte, and all data bytes in the
serial message. If this sum is greater than 0xFF, then the check sum byte equals the
least significant byte of the sum. The receiving module should recalculate the check
sum value once the message has been completely received. This calculated check
sum value should be compared against the message check sum value to verify that
the message has been received correctly.

The decoder board responds to each command message it receives from the external
controller board with a command acknowledge message. In a similar manner, the external
controller board responds to requests it receives from the decoder board with a request
acknowledge message.

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Serial Interface Design Specification Issued by: Videon Central, Inc.
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6. Supported Functions

Messages may travel from the external controller board to the decoder board or from the
decoder board to the external controller. All supported messages will be described in the
sections below.

6.1 Command List

The commands described in this section may be sent from the external controller board to the
decoder board.

6.1.1 Eject

Issues an eject command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x01 ------- 0x05

6.1.2 Power On

Places the system in the power on state.

6.1.3 Power Off

Places the system in the power off state.

6.1.4 Play

Issues a play command with a track number as the data. If track number 0 is
specified, then a normal play command is issued. If a non-zero track number
is specified, then a play track command with the given track number is
issued.

Data[0]: MSB of the track number
Data[1]: LSB of the track number
** Note: The data associated with this command is not currently used.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x02 ------- 0x06

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x03 ------- 0x07

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 4 0x02 0x04 Data Varies

6.1.5 Stop

Issues a stop command.

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Serial Interface Design Specification Issued by: Videon Central, Inc.
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SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x05 ------- 0x09

6.1.6 Pause

Issues a pause command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x06 ------- 0x0A

6.1.7 Track Up

Issues a track up command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x07 ------- 0x0B

6.1.8 Track Down

Issues a track down command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x08 ------- 0x0C

6.1.9 Slow Forward

Issues a slow forward command. Each successive command moves to the
next slow forward mode. These modes are valid for DVD only and are listed
below:

Slow Forward 1: Play 1/2 Real-time
Slow Forward 2: Play 1/4 Real-time
Slow Forward 3: Play 1/8 Real-time

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x09 ------- 0x0D

6.1.10 Fast Forward

Issues a fast forward command. Each successive command moves to the
next fast forward mode. These modes are dependant upon the disc source
and are listed below:

DVDV/DVDA: 2X, 4X, 8X, 16X, 30X, 60X
CD: 2X, 4X, 8X, 16X
MP3: 4X

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Serial Interface Design Specification Issued by: Videon Central, Inc.
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Note that for DVDV and CD, if a fast reverse command is issued while the
system is in a fast forward mode, the scan rate will be reduced. For example,
if the system is in fast forward 60X mode when a fast reverse command is
issued, the system will enter fast forward 30X mode. If the system is in fast
forward 2X mode when a fast reverse command is issued, the system will
enter normal play mode.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x0A ------- 0x0E

6.1.11 Un-rated Disc

If the OSD is generated and managed by the decoder board, this command is
intended for internal use only. Used to inform the serial interface task
running on the decoder board that un-rated disc has been inserted into the
drive.

If the OSD is generated and managed by the external controller board, this
command is not limited to internal use. Used to inform the external
controller board that un-rated disc has been inserted into the drive. Upon
receipt of this command, it is up to the external controller board to restrict or
not restrict playback depending on the current parental settings.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x0B ------- 0x0F

6.1.12 Angle Toggle

Increments the current angle by 1. If the last angle has been reached, the
current angle becomes the first angle. This command is only valid for
DVDV discs that contain multi-angle scenes. If any OSD is present on the
screen, this command is ignored.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x0C ------- 0x10

6.1.13 Display

Issues a display command. This command launches the full OSD status bar
for the current source without the associated OSD menu.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x0D ------- 0x11

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Serial Interface Design Specification Issued by: Videon Central, Inc.
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6.1.14 Restore Factory Defaults

Issues a restore factory defaults command. Restores the appropriate settings
to their factory default value. This command is only valid when there is no
disc in the drive.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x0E ------- 0x12

6.1.15 Frame Forward

Issues a single step command. The system must be in pause mode before this
command may be issued. This command is only valid for DVDV discs.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x10 ------- 0x14

6.1.16 Slow Reverse

Issues a slow reverse command. Each successive command moves to the
next slow reverse mode. These modes are valid for DVDV only and are
listed below:

Slow Reverse 1: Play 1/2 Real-time
Slow Reverse 2: Play 1/4 Real-time
Slow Reverse 3: Play 1/8 Real-time

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x11 ------- 0x15

6.1.17 Fast Reverse

Issues a fast reverse command. Each successive command moves to the next
fast reverse mode. These modes are dependant upon the disc source and are
listed below:

DVDV/DVDA: 2X, 4X, 8X, 16X, 30X, 60X
CD: 2X, 4X, 8X, 16X
MP3: 4X
Note that for DVDV and CD, if a fast forward command is issued while the

system is in a fast reverse mode, the scan rate will be reduced. For example,
if the system is in fast reverse 60X mode when a fast forward command is
issued, the system will enter fast reverse 30X mode. If the system is in fast
reverse 2X mode when a fast forward command is issued, the system will
enter normal play mode.

SYNC COUNT ID OPCODE DATA CK_SUM

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Serial Interface Design Specification Issued by: Videon Central, Inc.
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0xFE 2 0x02 0x12 ------- 0x16

6.1.18 Cursor Up

Issues a cursor up command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x13 ------- 0x17

6.1.19 Cursor Left

Issues a cursor left command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x14 ------- 0x18

6.1.20 Cursor Right

Issues a cursor right command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x15 ------- 0x19

6.1.21 Cursor Down

Issues a cursor down command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x16 ------- 0x1A

6.1.22 Enter

Issues an enter command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x17 ------- 0x1B

6.1.23 Disc Menu

Issues a disc menu command. This command is only valid for DVD discs
and is used to jump to the on disc DVD menu.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x18 ------- 0x1C

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Serial Interface Design Specification Issued by: Videon Central, Inc.
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6.1.24 Repeat

Cycles through the repeat modes available for the current disc source:
DVDV: Repeat Disc, Repeat Title, Repeat Chapter, Repeat Off
DVDA/CD/MP3: Repeat Disc, Repeat Track, Repeat Off

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x19 ------- 0x1D

6.1.25 Repeat Track

Issues a repeat track command. This command is only valid for
DVDA/CD/MP3 discs.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x1A ------- 0x1E

6.1.26 Random

Issues a random command. Toggles random mode on or off. The random
mode depends on the current disc source:

6.1.27 Audio

6.1.28 Subtitle

DVDV: Random Chapter
DVDA/CD/MP3: Random Track

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x1B ------- 0x1F

Issues an audio command to move to the next audio track. If the move is
successful, a status bar is displayed to indicate the new audio track. This
command is only valid for DVDV discs.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x1C ------- 0x20

Issues a subtitle command to move to the next subtitle. If the move is
successful, a status bar is displayed to indicate the new subtitle. This
command is only valid for DVDV discs.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x1D ------- 0x21

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Serial Interface Design Specification Issued by: Videon Central, Inc.
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6.1.29 Jump

Issues a jump command. This command is varies depending on the disc
source:

DVDV:
Data[0]: Chapter
Data[1]: Title
DVDA:
Data[0]: Track
Data[1]: Group
CD/MP3:
Data[0]: Track
Data[1]: Index (not referenced)

SYNC COUNT ID OPCODE DATA CK_SUM

6.1.30 Help

Issues a command to launch the appropriate help menu. This command is
only valid when the settings level OSD menu is active.

SYNC COUNT ID OPCODE DATA CK_SUM

6.1.31 Return

Issues a return command.

SYNC COUNT ID OPCODE DATA CK_SUM

6.1.32 Title Menu

Issues a title menu command. This command is only valid for DVDV discs.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 4 0x02 0x1E Data Varies

0xFE 2 0x02 0x1F ------- 0x23

0xFE 2 0x02 0x20 ------- 0x24

0xFE 2 0x02 0x21 ------- 0x25

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Serial Interface Design Specification Issued by: Videon Central, Inc.
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6.1.33 Repeat Chapter

Issues a repeat chapter command. This command is only valid for DVDV
discs.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x22 ------- 0x26

6.1.34 Repeat Title

Issues a repeat title command. This command is only valid for DVDV discs.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x23 ------- 0x27

6.1.35 Repeat Disc

Issues a repeat disc command.

SYNC COUNT ID OPCODE DATA CK_SUM

6.1.36 AB Repeat

Issues an AB repeat command. This command is only supported for DVDV
discs. Each successive command moves to the next stage of AB repeat.
These stages are listed below:

AB Repeat 1: Set point A
AB Repeat 2: Set point B and begin AB repeat
AB Repeat 3: Repeat off

SYNC COUNT ID OPCODE DATA CK_SUM

6.1.37 Repeat Off

Issues a repeat off command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x24 ------- 0x28

0xFE 2 0x02 0x25 ------- 0x29

0xFE 2 0x02 0x26 ------- 0x2A

6.1.38 Random On

Issues a random on command. This command is dependant upon the disc
source as shown below:

DVDV: Random Chapter

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Serial Interface Design Specification Issued by: Videon Central, Inc.
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DVDA/CD/ MP3: Random Track

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x27 ------- 0x2B

6.1.39 Random Off

Issues a random off command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x28 ------- 0x2C

6.1.40 0

Issues a number 0 command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x29 ------- 0x2D

6.1.41 1

6.1.42 2

6.1.43 3

Issues a number 1 command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x2A ------- 0x2E

Issues a number 2 command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x30 ------- 0x34

Issues a number 3 command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x31 ------- 0x35

6.1.44 4

Issues a number 4 command.

SYNC COUNT ID OPCODE DATA CK_SUM

0xFE 2 0x02 0x32 ------- 0x36

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