The long-transport test mode is used in all of the JMODE modes where N' equals 16. Patterns are generated in accordance with the JESD204B standard and are different for each output format as defined in Table 7-18. The rules for the pattern are defined below. Equation 11 gives the length of the test pattern. The long transport test pattern is the same for link A and link B, where DAx lanes belong to link A and DBx lanes belong to link B.
Equation 11. Long Test Pattern Length (Frames) = K × ceil[(M × S + 2) / K]
- Sample Data:
- Frame 0: Each sample contains N bits, with all samples set to the converter ID (CID) plus 1 (CID + 1). The CID is defined based on the converter number within the link; two links are used in all modes except JMODE 15. Within a link, the converters are numbered by channel (A or B) and in-phase (I) and quadrature-phase (Q) and reset between links. For instance, in JMODE 10, two links are used so channel A and B data are separated into separate links and the in-phase component for each channel has CID = 0 and the quadrature-phase component has CID = 1. In JMODE 15, one link is used, so channel A and B are within the same link and AI has CID = 0, AQ has CID = 1, BI has CID = 2, and BQ has CID = 3.
- Frame 1: Each sample contains N bits, with each sample (for each converter) set as its individual sample ID (SID) within the frame plus 1 (SID + 1)
- Frame 2 +: Each sample contains N bits, with the data set to 2N–1 for all samples (for example, if N is 15 then 2N–1 = 16384)
- Control Bits (if
CS > 0):
- Frame 0 to M × S – 1: The control bit belonging to the sample mod (i, S) of the converter floor (i, S) is set to 1 and all others are set to 0, where i is the frame index (i = 0 is the first frame of the pattern). Essentially, the control bit walks from the lowest indexed sample to the highest indexed sample and from the lowest indexed converter to the highest indexed converter, changing position every frame.
- Frame M × S +: All control bits are set to 0
Table 7-41 describes an example long transport test pattern for when JMODE = 10, K = 10.
Table 7-41 Example Long Transport Test Pattern (JMODE = 10, K = 10) | TIME → | | | | | | PATTERN REPEATS → |
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OCTET NUM | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 |
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DA0 | 0x0003 | 0x0002 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x0003 |
DA1 | 0x0004 | 0x0003 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x0004 |
DB0 | 0x0003 | 0x0002 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x0003 |
DB1 | 0x0004 | 0x0003 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x8000 | 0x0004 |
| Frame n | Frame n + 1 | Frame n + 2 | Frame n + 3 | Frame n + 4 | Frame n + 5 | Frame n + 6 | Frame n + 7 | Frame n + 8 | Frame n + 9 | Frame n + 10 |
The pattern starts at the end of the initial lane alignment sequence (ILAS) and repeats indefinitely as long as the link remains running. For more details see the JESD204B specification, section 5.1.6.3.