Figure 4. Service Command Parser Flowchart; Directv Set-Top Box Information For The Installer - DirecTV DTV-MD0-0058 Information For The Installer

DIRECTV Set-top box information for the installer

Start
Reset Command
Parser
(Parser is free)
NO
*Command
Prefix (0xFA)?
YES
**Command Parser
attaches to current
data port
(Parser is in use)
NO
*Known
Command?
YES
NO
*2 Byte
Command?
YES
nd
Read 2 Byte of a 2
Byte Command
NO
*Known
Command?
YES
Send
STB Response
= ACK_CMD
A
DIRECTV Proprietary
Version 1.1.a
Send
STB Response
= ACK_RESET
Send
STB Response
= NACK_PREFIX
Send
STB Response
= NACK_CMD

Figure 4. Service Command Parser Flowchart

Page 15 of 49
Send Send
STB Response STB Response
= DATA_ERROR = CMDBUF_OVFL
Send
STB Response
= NACK_PARAMS
Send
STB Response
= NACK_FCNOK
A
NO
Input
Parameters?
YES
*Correct # of
NO
Input
Parameters?
YES
Send
STB Response
= ACK_PARAMS
Execute Command
and send Return
Data Stream as
appropriate
(Parser is Busy)
Command
NO
completed
successfully ?
YES
Send
STB Response
= ACK_FCNOK
(Parser is not busy)
November 17, 2005
DTV-MD-0058