STM8SPLNB1 STMicroelectronics, STM8SPLNB1 Datasheet - Page 40

• Manufacturer Part Number: STM8SPLNB1
• Description: DiSEqC slave microcontroller for SaTCR based LNBs and switchers
• Manufacturer: STMicroelectronics

DiSEqC™ protocol basics
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For more detailed information about DiSEqC™ protocol - see DiSEqC™ bus functional
specifications and DiSEqC™ slave microcontroller specifications. Refer to
www.eutelsat.com website.
Protocol layer
The DiSEqC™ messages are transferred in packets. One packet consists from several
bytes - each byte has 8 bits followed by parity bit (odd).
The full DiSEqC™ message contains a frame byte, an address byte, a command byte which
can be followed by several data bytes.
Figure 21. DiSEqC™ message format
When host is requesting an answer from the slave (microcontroller) then the answer
consists from frame byte which can be followed by several data bytes
Figure 22. Microcontroller answer format.
The frame byte identifies the direction, reply requirements and error status - see following
Table 35.
Table 35.
The address byte identifies the receiver. There also exist address groups (families). The
family address is valid for all devices with similar (family) function - all given family devices
receive message. Address families are described in DiSEqC™ slave microcontroller
specifications. Universal (broadcast) address is 0x00 - all devices should receive messages
with this address.
Command byte describes given command for device - according this command the device
selects method for data processing.
Frame byte
0xE0
0xE1
0xE2
0xE3
0xE4
0xE5
0xE6
0xE7
DiSEqC™ frame byte definition
Command from master, no reply required, first transmission
Command from master, no reply required, repeated transmission
Command from master, reply required, first transmission
Command from master, reply required, repeated transmission
Reply from slave, OK, no errors found
Reply from slave, command not supported
Reply from slave, parity error, repeat requested
Reply from slave, command not recognized, repeat necessary
Doc ID 018831 Rev 3
definition
STM8SPLNB1