SBASB21 September 2024 DDS39RF12 , DDS39RFS12
PRODUCTION DATA
The device JESD204C modes are configured with the parameters defined in Table 7-19, Table 7-20 and Table 7-21.
Parameter | Description |
---|---|
JMODE | JESD204C mode number. The user configures this parameter to choose a supported mode. Most other parameters are derived from this setting. See Table 7-22. |
LS | Lanes per sample stream. This is derived from JMODE. See Table 7-22. |
LT | Ratio of clock to input sample rate. LT = FCLK / FINPUT.
Not that DES2X mode
does not affect the value of LT. Interpolation factor 1-256x is programmed in the DUC_L register. |
Lx | Maximum number of lanes used for a given JMODE. The link scales down the number of active lanes (L) depending on how many channels are enabled. See JESD_M register. |
Mx | Maximum number of streams for a given JMODE. Mx is computed automatically according to Table 7-22. The user can specify the actual number of streams (M) using the JESD_M register. |
R | Number of bits transmitted per lane per CLK cycle. Derived from JMODE and LT (see )Table 7-22. Based on R, the user must program REFDIV, MPY, and RATE registers. Additionally, the maximum CLK frequency is a function of R. |
SI | Sample Interleaving/Increment Factor. A value of 1 indicates that the standard transport layer mapping from the JESD204C standard is used (samples are mapped linearly from 0 to S-1). A value greater than 1 indicates that an alternate mapping is used as follows: Map samples starting with sample 0, incrementing the index by SI. Repeat this as many times as necessary to map all S samples, starting each repetition at an index that is one larger than the previous repetition. See JESD Format Diagrams JESD Format Diagrams. |
KR | For 8b/10b operation, KR defines the legal values of K (frames per multiframe). The legal values are restricted to facilitate upset immunity of the elastic buffer. The multiframe length is restricted to a multiple of the elastic buffer depth of 64 characters (buffer depth is reduced to 32 characters if K=32 and F=1). For 8b/10b modes, K is programmed via the KM1 register. |
Parameter | Description | ILAS Field Name | Value for this device(1) |
---|---|---|---|
ADJCNT | DAC LMFC adjustment | ADJCNT[3:0] | n/a |
ADJDIR | DAC LMFC adjustment direction | ADJDIR[0] | n/a |
BID | Bank ID | BID[3:0] | n/a |
CF | Number of control words per frame | CF[4:0] | 0 |
CS | Number. of control bits per sample | CS[1:0] | 0 |
DID | Device identification number | DID[7:0] | n/a |
F | Number of octets per frame (per lane) | F[7:0] | See Table 7-22 |
HD | High Density Format | HD[0] | See Table 7-22 |
JESDV | JESD204 Version | JESDV[2:0] | n/a |
K | Number of frames per multiframe | K[7:0] | Set by KM1register |
L | Number of lanes per link | L[4:0] | ceiling(M/Mx*Lx) |
LID | Lane identification no. | LID[4:0] | n/a |
M | Number of sample streams per link (see (1)) | M[7:0] | Set by JESD_M register |
N | Bits per sample (before adding control or tail bits) for JESD204C interface. | N[4:0] | See Table 7-22 |
N' | Total number of bits per sample (including control and tail bits) for JESD204C interface. | N’[4:0] | See Table 7-22 |
PHADJ | Phase adjustment request to DAC | PHADJ[0] | n/a |
S | Number of samples per stream per frame | S[4:0] | See Table 7-22 |
SCR | Scrambling enabled | SCR[0] | Set by SCR register |
SUBCLASSV | Device Subclass Version | SUBCLASSV[2:0] | n/a |
RES1 | Reserved field 1 | RES1[7:0] | n/a |
RES2 | Reserved field 2 | RES2[7:0] | n/a |
CHKSUM | Checksum (sum of all above fields, modulo 256) | FCHK[7:0] | n/a |
Parameter | Description | Value for this device(1) |
---|---|---|
E | Number of multi-blocks per extended multi-block (64b/66b encoding only) | 1 |
Each supported mode is assigned a mode number which can be programmed into the JMODE register with the parameters listed in Table 7-22.
JMODE | Encoding | Max Input Sample Rate per Stream (MSPS)#GUID-6D01121F-27FF-4679-9595-503775437EB9 | MAX Serdes Baud Rate (Gbps) | R = FBIT/ FCLK |
N | Mx = Max # Streams | Ls = Lanes/Stream | Lx = Max # Lanes | LT = Interpolation | JESD Format | KR | ||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
MIN | MAX | F | S | HD | SI | ||||||||||
4 | 8b/10b | 640 | 12.8 | 20/LT | 16 | 2 | 1 | 2 | 4 | 64 | 2 | 1 | 0 | 1 | 32, 64, 128 |
64b/66b | 775.8 | 12.8 | 16.5/LT | ||||||||||||
5 | 8b/10b | 320 | 12.8 | 40/LT | 16 | 4 | ½ | 2 | 8 | 128 | 4 | 1 | 0 | 1 | 16,32,64 |
64b/66b | 387.9 | 12.8 | 33/LT | ||||||||||||
6 | 8b/10b | 160 | 12.8 | 80/LT | 16 | 8 | ¼ | 2 | 16 | 256 | 8 | 1 | 0 | 1 | 8,16,32 |
64b/66b | 193.9 | 12.8 | 66/LT | ||||||||||||
7 | 8b/10b | 80 | 12.8 | 160/LT | 16 | 8 | ⅛ | 1 | 32 | 256 | 16 | 1 | 0 | 1 | 4,8,16 |
64b/66b | 97.0 | 12.8 | 132/LT |