Onfidential – Denon DVD-757 User Manual

Page 4

Ver 2.01

Date : Nov.29.2005

4 page of 46

1.3

Command format and answer format

This unit shall be based on commands each of which consists of a data row ( some commands
are without a PC ) composed of command codes ( CC ) and parameter codes ( PC ) . The
trans-mitting station shall be designed to send block check characters ( BCC ) following ETX,
with the data row enclosed in STX ( text start : 02h ) and ETX ( text termination : 03h ) .
The receiving station shall regard receipt of BCC as the completion of command reception when
it has received STX.

Here are the formats.

Commands : <--------->

STX (Start of TeXt)

: 02h

CC (Command Code)

: Command code

PC (Parameter Code)

: Defined for each command

( contents and number of parameters )

ETX (End of TeXt)

: 03h

BCC (Block Check Character) :

CC + PC0 + PC1 + PC2 + --------------- + PCn + ETX = XYh

(Each of X and Y is 4 bit long ) X , Y=0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F

BCCH ( high-level byte ) = X as converted to an ASCII code

BCCL ( low-level byte ) = Y as converted to an ASCII

code

Answers : <-------->

STX (Start of TeXt)

: 02h

RC (Reply Code)

: Reply code (=Command code)

AC (Answer Code)

: Answer code

PC (Parameter Code)

: Defined for each command

( contents and number of parameters )

ETX (End of TeXt)

: 03h

BCC (Block Check Character) :

RC +AC + PC0 + PC1 + PC2 + ------------- + PCn + ETX = XYh

(Each of X and Y is 4 bit long) X ,
Y=0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F

BCCH ( high-level byte ) = X as converted to an ASCII code

BCCL ( low-level byte ) = Y as converted to an ASCII

code

1.4

Protocol for data transmission and reception

This unit is based on half-duplex communication. The unit shall therefore transmit commands
and receive answers according to the following procedure.

1.4.1

Basic procedure

The host shall select commands for this unit and transmit them to this unit. Command

interval time is MIN 40µsec.

Having issued a command, the host shall receive an answer from this unit, then issue

the next command.

The host shall analyze the RC, AC, and PC as answers given and decide whether the

NFIDENTIAL