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1 SYM
1 SYM
3 SYM
3 SYM
Bit 1
Bit 0
Figure 35. 1527 Bit Format Options
5.1.7 2262 Packet Structure
The traditional 2262 packet contains an Address (Sync ID), a Data, and a 32-symbol Sync. In 2262 mode the device does not
support ID study.
Figure 36. 2262 Packet Structure
Table 13. Configurable Parameters in 2262 Packet
Parameter
Descriptions
Default
Mode
Address (Sync ID)
Length
This is the range of the Sync ID Length. The range is from
8 to 11 bits.
8 bits
Basic
Advanced
Address (Sync ID)
Value
Each bit of the Sync ID can have the value of 0, 1 or f,
where f represents “floating” according to the original 2262
definitions.
00000000
Basic
Advanced
Sync
The Sync is 1 high symbol followed by 31 low symbols.
The user can determine whether or not to introduce
tolerance of detecting the 31 low symbols. The options are:
No Tolerance, +/- 6 symbols, +/- 13 symbols, or +/- 20
symbols
+/- 13 symbols
Basic
Advanced
In the traditional 2262 format, 4 OSC clocks (1 OSC clock cycle is notated as 1
α
) are equal to 1 symbol. By using the CMOSTEK
products, the user does not need to adjust the OSC to define the symbol rate, because the symbol rate is directly programmed.
The Bit Format is fixed at 8 symbols per bit.
Address (Sync ID)
The Sync ID is sent and received starting from the LSB. For example, if the “Sync ID Value” is set to 1, the binary value of the
Sync ID is “00000001”. In this case, bit<0> = 1 is received first and bit<7> = 0 is received at the end of the Sync ID field. For
example, if the Sync ID Length is set to 8, the value sent by the CMT2150A can be 10f0f101.
The traditional 2262 can support up to 6 data pins. However, the maximum number of data output pins is 4 for CMT2250A. In this
case, the length of the Data is configurable from 1 to 4 bits. Correspondingly, the length of the Sync ID is configurable from 11 to
8 bits. The total number of bits of the Sync ID and Data is always fixed at 12.
Data
These are the length-configurable data bits received to control the 4 data pins. As introduced above, the length of the data field
automatically configured according to that of the Address (Sync ID) field. Please note that, differing from the 1920 and 1527, the
MSB of data is received first, e.g. if 4 data bits are transmitted, D3 is received first.
