8.3.6 JESD204B Frame Assembly
The DAC38RF82 (or DAC38RF89) may be programmed as a single or dual DAC device, with one JESD RX block designated for each DAC. The two JESD RX blocks can be programmed to operate as two separate links or as a single link.
The JESD204B defines the following parameters:
- L is the number of lanes
- M is the number of I or Q streams per device (2 = 1 IQ pair, 4 = 2 IQ pairs, 8 = 4 IQ pairs)
- F is the number of octets per frame clock period
- S is the number of samples per frame
- HD is the High-Density bit which controls whether a sample may be divided over more lanes
- N = NPRIME is the number of bits per sample (12 or 16 - bits)
Fields K and L are found in multi-DUC paged register JESD_K_L (8.5.46), M and S in multi-DUC paged register JESD_M_S (8.5.48), and N, NPRIME and HD in multi-DUC paged register JESD_N_HD_SCR (8.5.49).
Table 9 lists the available JESD204B formats, interpolation rates and sample rate limits for the DAC38RF82 (or DAC38RF89). The ranges are limited by the SerDes PLL VCO frequency range, the SerDes PLL reference clock range, the maximum SerDes line rate, and the maximum DAC sample frequency. Table 10 through Table 27 lists the frame formats for each mode. In the frame format tables, i CH (N) [x:y] and q CH (N) [x:y] are bits x through y of the I and Q samples at time N of DUC channel CH. If [x..y] is not listed, the full sample is assumed. For example, i0(0)[15:8] are bits 15 – 8 of the I sample at time 0, and q(1) is the full Q sample at time 1.
Table 9. JESD204B Formats for DAC38RF82 and DAC38RF89
L-M-F-S-Hd
1 TX |
L-M-F-S-Hd
2 TX |
Frame Format |
Input Resolution |
IQ pairs per DAC |
Interp |
Input rate max (MSPS) |
fDAC Max (MSPS) |
82121 |
NA |
1 TX: Table 10 |
16 |
1 |
6 |
1500 |
9000 |
16 |
1 |
8 |
1125 |
9000 |
16 |
1 |
12 |
750 |
9000 |
16 |
1 |
16 |
562.5 |
9000 |
42111 |
84111 |
1 TX: Table 11
2 TX: Table 12 |
16 |
1 |
6 |
1250 |
7500 |
16 |
1 |
8 |
1125 |
9000 |
16 |
1 |
10 |
900 |
9000 |
16 |
1 |
12 |
750 |
9000 |
16 |
1 |
16 |
562.5 |
9000 |
16 |
1 |
18 |
500 |
9000 |
16 |
1 |
24 |
375 |
9000 |
22210 |
44210 |
1 TX: Table 13
2 TX: Table 14 |
16 |
1 |
8 |
625 |
5000 |
16 |
1 |
12 |
625 |
7500 |
16 |
1 |
16 |
562.5 |
9000 |
16 |
1 |
18 |
500 |
9000 |
16 |
1 |
20 |
450 |
9000 |
16 |
1 |
24 |
375 |
9000 |
12410 |
24410 |
1 TX: Table 15
2 TX: Table 16 |
16 |
1 |
16 |
312.5 |
5000 |
16 |
1 |
24 |
312.5 |
7500 |
44210 |
88210 |
1 TX: Table 17
2 TX: Table 18 |
16 |
2 |
8 |
625 |
5000 |
16 |
2 |
12 |
625 |
7500 |
16 |
2 |
16 |
562.5 |
9000 |
16 |
2 |
24 |
375 |
9000 |
24410 |
48410 |
1 TX: Table 19
2 TX: Table 20 |
16 |
2 |
16 |
312.5 |
5000 |
16 |
2 |
24 |
312.5 |
7500 |
24310 |
48310 |
1 TX: Table 21
2 TX: Table 22 |
12 |
2 |
24 |
375 |
9000 |
81180 |
NA |
1 TX: Table 23 |
8 |
real input |
1 |
9000 |
9000 |
41380 |
82380 |
1 TX: Table 24
2 TX: Table 25 |
12 |
real input(1) |
1 |
3333 |
3333 |
2 |
3333 |
6666 |
41121 |
82121 |
1 TX: Table 26
2 TX: Table 27 |
16 |
real input(1) |
1 |
2500 |
2500 |
2 |
2500 |
5000 |
4 |
2250 |
9000 |
Table 10. JESD204B Frame Format for LMFSHd = 82121
# un bits |
4 |
8 |
# en bits |
5 |
10 |
Nibble |
1 |
2 |
lane RX0 |
i0[15:8] |
lane RX1 |
i0[7:0] |
lane RX2 |
i1[15:8] |
lane RX3 |
i1[7:0] |
lane RX4 |
q0[15:8] |
lane RX5 |
q0[7:0] |
lane RX6 |
q1[15:8] |
lane RX7 |
q1[7:0] |
Table 11. JESD204B Frame Format for LMFSHd = 42111
# un bits |
4 |
8 |
# en bits |
5 |
10 |
Nibble |
1 |
2 |
lane RX0 |
i0[15:8] |
lane RX1 |
i0[7:0] |
lane RX2 |
q0[15:8] |
lane RX3 |
q0[7:0] |
Table 12. JESD204B Frame Format for LMFSHd = 84111
# un bits |
4 |
8 |
# en bits |
5 |
10 |
Nibble |
1 |
2 |
lane RX0 |
A-i0[15:8](1) |
lane RX1 |
A-i0[7:0](2) |
lane RX2 |
A-q0[15:8] |
lane RX3 |
A-q0[7:0] |
lane RX4 |
B-i0[15:8] |
lane RX5 |
B-i0[7:0] |
lane RX6 |
B-q0[15:8] |
lane RX7 |
B-q0[7:0] |
(1) DAC A, I sample 0, MSB byte
(2) DAC A, I sample 0, LSB byte
Table 13. JESD204B Frame Format for LMFSHd = 22210
# un bits |
4 |
8 |
12 |
16 |
# en bits |
5 |
10 |
15 |
20 |
Nibble |
1 |
2 |
3 |
4 |
lane RX0 |
i0 |
lane RX1 |
q0 |
Table 14. JESD204B Frame Format for LMFSHd = 44210
# un bits |
4 |
8 |
12 |
16 |
# en bits |
5 |
10 |
15 |
20 |
Nibble |
1 |
2 |
3 |
4 |
lane RX0 |
A-i0(1) |
lane RX1 |
A-q0 |
lane RX2 |
B-i0 |
lane RX3 |
B-q0 |
(1) DAC A, I sample 0
Table 15. JESD204B Frame Format for LMFSHd = 12410
# un bits |
4 |
8 |
12 |
16 |
20 |
24 |
28 |
32 |
# en bits |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
40 |
Nibble |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
lane RX0 |
i0 |
q0 |
Table 16. JESD204B Frame Format for LMFSHd = 24410
# un bits |
4 |
8 |
12 |
16 |
20 |
24 |
28 |
32 |
# en bits |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
40 |
Nibble |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
lane RX0 |
A-i0(1) |
A-q0 |
lane RX1 |
B-i0 |
B-q0 |
(1) DAC A, I sample 0
Table 17. JESD204B Frame Format for LMFSHd = 44210
# un bits |
4 |
8 |
12 |
16 |
# en bits |
5 |
10 |
15 |
20 |
Nibble |
1 |
2 |
3 |
4 |
lane RX0 |
A1-i0(1) |
lane RX1 |
A1-q0(2) |
lane RX2 |
A2-i0 |
lane RX3 |
A2-q0 |
(1) DAC A, MultiDUC 1, I sample 0
(2) DAC A, MultiDUC 2, I sample 0
Table 18. JESD204B Frame Format for LMFSHd = 88210
# un bits |
4 |
8 |
12 |
16 |
# en bits |
5 |
10 |
15 |
20 |
Nibble |
1 |
2 |
3 |
4 |
lane RX0 |
A1-i0(1) |
lane RX1 |
A1-q0 |
lane RX2 |
A2-i0 |
lane RX3 |
A2-q0 |
lane RX4 |
B1-i0 |
lane RX5 |
B1-q0 |
lane RX6 |
B2-i0 |
lane RX7 |
B1-q0 |
(1) DAC A, MultiDUC 1, I sample 0
Table 19. JESD204B Frame Format for LMFSHd = 24410
# un bits |
4 |
8 |
12 |
16 |
20 |
24 |
28 |
32 |
# en bits |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
40 |
Nibble |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
lane RX0 |
A1-i0(1) |
A1-q0 |
lane RX1 |
A2-i0 |
A2-q0 |
(1) DAC A, MultiDUC 1, I sample 0
Table 20. JESD204B Frame Format for LMFSHd = 48410
# un bits |
4 |
8 |
12 |
16 |
20 |
24 |
28 |
32 |
# en bits |
5 |
10 |
15 |
20 |
25 |
30 |
35 |
40 |
Nibble |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
lane RX0 |
A1-i0(1) |
A1-q0 |
lane RX1 |
A2-i0 |
A2-q0 |
lane RX2 |
B1-i0 |
B1-q0 |
lane RX3 |
B2-i0 |
B2-q0 |
(1) DAC A, MultiDUC 1, I sample 0
Table 21. JESD204B Frame Format for LMFSHd = 24310
# un bits |
4 |
8 |
12 |
16 |
20 |
24 |
# en bits |
5 |
10 |
15 |
20 |
25 |
30 |
Nibble |
1 |
2 |
3 |
4 |
5 |
6 |
lane RX0 |
A1-i0(1) |
A1-q0 |
lane RX1 |
A2-i0 |
A2-q0 |
(1) DAC A, MultiDUC 1, I sample 0
Table 22. JESD204B Frame Format for LMFSHd = 48310
# un bits |
4 |
8 |
12 |
16 |
20 |
24 |
# en bits |
5 |
10 |
15 |
20 |
25 |
30 |
Nibble |
1 |
2 |
3 |
4 |
5 |
6 |
lane RX0 |
A1-i0(1) |
A1-q0 |
lane RX1 |
A2-i0 |
A2-q0 |
lane RX2 |
B1-i0 |
B1-q0 |
lane RX3 |
B2-i0 |
B2-q0 |
(1) DAC A, MultiDUC 1, I sample 0
Table 23. JESD204B Frame Format for LMFSHd = 81180
# un bits |
4 |
8 |
# en bits |
5 |
10 |
Nibble |
1 |
2 |
lane RX0 |
A0(1) |
lane RX1 |
A1 |
lane RX2 |
A2 |
lane RX3 |
A3 |
lane RX4 |
A4 |
lane RX5 |
A5 |
lane RX6 |
A6 |
lane RX7 |
A7 |
(1) DAC A, sample 0
Table 24. JESD204B Frame Format for LMFSHd = 41380
# un bits |
4 |
8 |
12 |
16 |
20 |
24 |
# en bits |
5 |
10 |
15 |
20 |
25 |
30 |
Nibble |
1 |
2 |
3 |
4 |
5 |
6 |
lane 0 |
A-0(1) |
A-1 |
lane 1 |
A-2 |
A-3 |
lane 2 |
A-4 |
A-5 |
lane 3 |
A-6 |
A-7 |
(1) DAC A, sample 0
Table 25. JESD204B Frame Format for LMFSHd = 82380
# un bits |
4 |
8 |
12 |
16 |
20 |
24 |
# en bits |
5 |
10 |
15 |
20 |
25 |
30 |
Nibble |
1 |
2 |
3 |
4 |
5 |
6 |
lane 0 |
i(0) |
i(1) |
lane 1 |
i(2) |
i(3) |
lane 2 |
i(4) |
i(5) |
lane 3 |
i(6) |
i(7) |
lane 4 |
q(0) |
q(1) |
lane 5 |
q(2) |
q(3) |
lane 6 |
q(4) |
q(5) |
lane 7 |
q(6) |
q(7) |
Table 26. JESD204B Frame Format for LMFSHd = 41121
# un bits |
4 |
8 |
# en bits |
5 |
10 |
Nibble |
1 |
2 |
lane 0 |
A-0[15:8](1) |
lane 1 |
A-0[7:0](2) |
lane 2 |
A-1[15:8] |
lane 3 |
A-1[7:0] |
(1) DAC A, sample 0, MSB byte
(2) DAC A, sample 0, LSB byte
Table 27. JESD204B Frame Format for LMFSHd = 82121
# un bits |
4 |
8 |
# en bits |
5 |
10 |
Nibble |
1 |
2 |
lane RX0 |
A-0[15:8](1) |
lane RX1 |
A-0[7:0](2) |
lane RX2 |
A-1[15:8] |
lane RX3 |
A-1[7:0] |
lane RX4 |
B-0[15:8] |
lane RX5 |
B-0[7:0] |
lane RX6 |
B-1[15:8] |
lane RX7 |
B-1[7:0] |
(1) DAC A, sample 0, MSB byte
(2) DAC A, sample 0, LSB byte