Help: ICE_IOC_FMDE
Handles framing of FMDE signals
Each sample of data and time code is packed and presented as 8 bytes.
Therefore, all data whether it be true data or time code is on an 8 byte
boundary when acquired.
A sample is determined to be valid if byte 4 (the 5th byte) is a non-zero value.
This non-zero value is the composite sync packed into 8 bits. Bytes 0 through
4, in order, are NDU, DU, NSPU, SPU.
If byte 4 is a zero, then the sample is time code. The first 4 bytes
represent the time code in LSB to MSB order. This is different from an earlier
version that represented time code in MSB to LSB order within the 8 byte
time code long word. (long word = 8 bytes)
For FMDE data (not Time Code), the Most Significant 3 Bytes contain a 24 bit
count-with the MSByte occurring in the MSByte of the 8 byte data long word.
This count represents the number of clocks from the detection of the latest
time code barker code. In other words, this is the clock count from the
prior arriving time code.
For FMDE time code, the Most Significant 3 Bytes contain a 24 bit count-with
the MSByte occurring in the MSByte of the 8 byte time code long word. This
represents the number of clocks from the detection of the PRECEDING time
code barker code. In other words, this is the clock count from the prior
arriving time code.
In summary,
Byte order for 8 bytes of data,
1st BYTE 8th Byte
NDU, DU,NSPU,SPU,CSYNC,LSB Count,MIDDLE Count,MSB Count -- DATA
TC LSB BYTE,TC,TC,TC MSB BYTE,ZERO,LSB Count,MIDDLE Count,MSB Count -- Time Code
Because the ICE card interface is 16 bits the following bits are
assumed to contain FMDE data.
Bit 4 Time Code
Bit 6 NDU Stream
Bit 7 DU Stream
Bit 8 NSPU Stream
Bit 9 SPU Stream
Bit 10 CSYNC Stream
Note-Bit 4 is the 5th bit. (Bit numbering-0,1,2,3,4,5,...,15)
Connecting the 10 bit FMDE cable to the 16 bit ICE transition
panel will yield correct bit connections.