SBAS932 March 2024 DAC39RF10-SEP , DAC39RF10-SP , DAC39RFS10-SEP , DAC39RFS10-SP
PRODMIX
The devices uses a JESD204C high-speed serial interface to transfer data from the logic device to the receiving DAC. The device serial lanes are capable of operating with both 8b/10b encoding and 64b/66b encoding. The JESD204C formats using 8b/10b encoding are backwards compatible with existing JESD204B receivers. A maximum of 16 lanes can be used to lower lane rates for interfacing with speed limited logic devices. There are a few differences between 8b/10b and 64b/66b encoding, which is highlighted throughout this section. Figure 7-50 shows a simplified block diagram of the 8b/10b encoded JESD204C interface and Figure 7-51 shows a simplified block diagram of the 64b/66b encoded JESD204C interface.
Figure 7-50 Simplified JESD204C Interface Diagram with 8b/10b EncodingNot all optional features of JESD204C are supported by the device. The list of features that are supported and the features that are not supported is provided in Table 7-15
| LETTER IDENTIFIER | FEATURE | SUPPORTED BY DEVICE? |
|---|---|---|
| a | 8b/10b link layer | Yes |
| b | 64b/66b link layer | Yes |
| c | 64b/80b link layer | No |
| d | The command channel when using 64b/66b or 64b/80b link layer | No |
| e | Forward error correction (FEC) when using the 64b/66b or 64b/80b link layer | No |
| f | CRC3 when using the 64b/66b or 64b/80b link layer | No |
| g | A physical SYNC pin when using the 8b/10b link layer | Yes |
| h | Subclass 0 | Yes |
| i | Subclass 1 | Yes |
| j | Subclass 2 | No |
| k | Lane alignment within a single link | Yes |
| l | Subclass 1 with support for lane alignment on a multipoint link by means of the MULTIREF signal | No |
| m | SYNC interface timing compatible with JESD204A | Yes |
| n | SYNC interface timing compatible with JESD204B | Yes |
The various signals used in the JESD204C interface and the associated device pin names are summarized briefly in Table 7-16 for reference.
| SIGNAL NAME | DEVICE PIN NAMES | DESCRIPTION |
|---|---|---|
| Data | [15:0]SRX± | High-speed serialized data after 8b/10b or 64b/66b encoding that is received by the SerDes receivers. |
| SYNC | SYNC | Link initialization signal (handshake), toggles low to start code group synchronization (CGS) process. Not used for 64B/66B encoding modes. |
| Device clock | CLK+, CLK– | DAC sampling clock, also used for clocking digital logic and SerDes receivers. |
| SYSREF | SYSREF+, SYSREF– | System timing reference used to deterministically reset the internal local multiframe clock (LMFC) or local extended multiblock clock (LEMC) counters in each JESD204C device |