SRC4190 (does 24-bit Left Justified input support a 32-bit frame)?

Richard Kim1

Other Parts Discussed in Thread: SRC4190

We plan to use the SRC4190 in "24-Bit LEFT Justified" input format and "24-bit/Left Justified" output format. Both input and output are in Slave-mode.

For the input format, the datasheet says the "audio data word length may be up to 24 bits for I2S and Left Justified formats".

Figure 4a appears to show a case where the data bits per channel can be up to 24-bits and the total frame word length is 64= 32 (left channel)+32 (right-channel) bits, i.e. the 24-bit data is padded with 8 zero bits per channel.

In this input-mode, can the SRC4190 handle a case where the data is 16-bits and the total word frame is 32-bits= 16 (left channel) + 16 (right-channel) i.e. no extra bit padding? Or do we have to use 16-bit Right Justified?

Thanks,

Rich

over 9 years ago

0 Richard Kim1 over 9 years ago

Prodigy 20 points

It turns out the SRC4190 expects 32-bits per left/right channel for a total of 64-bits per frame (at least in 24-bit Left Justified input mode). So 16-bit data with a 32-bit frame does NOT work.

0 Justin Bohr over 9 years ago in reply to Richard Kim1

TI__Mastermind 28020 points

Hi Richard,

Thanks for posting your results, I was just about to post that I had not tested this personally, but suspected the system would work only if 32 bits per frame were allotted with the BCK to LRCK ratio when in 24 bit mode.

Justin

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SRC4190 (does 24-bit Left Justified input support a 32-bit frame)?