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Following this are 64 (or 48 or 32) bytes of programming data. The first two bytes are for channel 31 (or 23 or 15) and the last two bytes are for channel 0. Each channel has 14 bits, so the format is two leading zeros and 6 MSB of data is the first byte, then 8 LSB of data in the second byte. All channels are present in the packet, but only those marked in the mask will be programmed; all other bytes will be ignored and can take on any value. The total size of the data in a programming packet is:
Following this are 64 (or 48 or 32) bytes of programming data. The first two bytes are for channel 31 (or 23 or 15) and the last two bytes are for channel 0. Each channel has 14 bits, so the format is two leading zeros and 6 MSB of data is the first byte, then 8 LSB of data in the second byte. All channels are present in the packet, but only those marked in the mask will be programmed; all other bytes will be ignored and can take on any value. The total size of the data in a programming packet is:
{| align="center" cellpadding="8" border="0" cellspacing="4" style="text-align:center"
{| align="center" cellpadding="4" border="0" cellspacing="0" style="text-align:center"
! Number of channels
! Number of channels
|
! Data Bytes per Packet
! Data Bytes per Packet
|-
|-
| 32 || 69
| 32 || || 69
|-
|-
| 24 || 52
| 24 || || 52
|-
|-
| 16 || 35<sup>*</sup>
| 16 || || 35<sup>*</sup>
|}
|}
Since the minimum number of data bytes in a packet is 46, the packet may need to be padded if only 16 channels are to be used. Padding may not be necessary if the PC includes layer 3 and layer 4 data. Alternately the mask can be eliminated, forcing all channels of the DAC to be reprogrammed every programming cycle.
Since the minimum number of data bytes in a packet is 46, the packet may need to be padded if only 16 channels are to be used. Padding may not be necessary if the PC includes layer 3 and layer 4 data. Alternately the mask can be eliminated, forcing all channels of the DAC to be reprogrammed every programming cycle.