Logical Addressing; Logical Address Allocation; Table 1. Logical Addresses - ST STM32F100 Series Application Note

AN3127 High-definition multimedia interface, consumer electronics control (HDMI-CEC)
Whenever a new physical address (other than F.F.F.F) is discovered, a CEC device should:
●
allocate the logical address (see
● report the association between its logical and physical addresses by broadcasting
<Report Physical Address>
This process allows any node to create a map of physical connections to logical addresses.
1.4.6

Logical addressing

Apart from the physical address, each device appearing on the control signal line has a
unique logical address. This address defines a device type as well as being a unique
identifier. This address is 0 for a TV set with physical address 0b0000 and 14 or even 15
otherwise. It is defined in the CEC_OAR register and in the upper nibble of the first byte of
the transmitted message. All CEC devices therefore have both a physical and a logical
address, whereas non-CEC devices only have a physical address.
Table 1.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1.4.7

Logical address allocation

Note that a logical address should only be allocated when a device has a valid physical
address (i.e. not F.F.F.F), at all other times a device should take the 'Unregistered' logical
address (15).
Only the device at physical address 0.0.0.0 may take logical address TV (0). A TV at any
other physical address will take the 'free use' (14) address. If address 14 is already
allocated it will take the 'unregistered' address (15).
Logical addresses
Address
Doc ID 16896 Rev 2
Section 1.4.7: Logical address
TV
Recording device 1
Recording device 2
Tuner 1
Playback device 1
Audio system
Tuner 2
Tuner 3
Playback device 2
Recording device 3
Tuner 4
Playback device 3
Reserved
Reserved
Free use
Unregistered (as initiator address) broadcast (as destination
address)
allocation)
Device
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