ADC12DJ5200RF: JMODE30

Peleg Aviely

JESD204C 64b/66b, mode 30, includes 12bit samples.

Table 7.4.4.1 in https://www.ti.com/lit/ds/slvsen9c/slvsen9c.pdf?ts=1655899655282, JMODE 30, specify E=1, F=8, N'=N=12bit.

Does it mean there are 4 tail bits in the 8 octet frame ?

over 4 years ago

0 Neeraj Gill over 4 years ago

TI__Mastermind 20541 points

Hi Peleg,

Here is the frame for JMODE30. As you can see per frame there are 8 octets and 4 tail bits.

Regards,

Neeraj

0 Peleg Aviely over 4 years ago in reply to Neeraj Gill

Prodigy 10 points

Thanks Neeraj.
It seems like JMODE list is missing this important parameter of tail bits.

Another aspect of this is the loss of efficiency. Instead of using 3 frames of 8 octets to send 16 X 12bit samples with 64/66=~97% efficiency, 5 X 12bit samples are sent with 60/66=91% efficiency.

Loosing 6% of the throughput is not a small thing.

Is there any intention to optimize this in future devices ?

0 Neeraj Gill over 4 years ago in reply to Peleg Aviely

TI__Mastermind 20541 points

there are also other modes such JMODE42 where the packing is much more tighter but it uses 12 lanes instead of 8 lanes.

Regards,

Neeraj

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ADC12DJ5200RF: JMODE30