AD1955 only 4 registers.
How to use SPI read AD1955 register? What's read CMD?
Pls. help to show the AD1955 read/write format, thx!
The AD1955 does not have the ability to transmit its register settings back to a SPI host; please note that there is no COUT (MISO) pin on the part. The Control Register address for a individual register write is set by the 2 LSB of the 2-byte word, with the other 14 bits as register data. Please find Tables I - III on page 14 for reference.
I moved this question about the AD1955 to the Audio Community. Someone here should be able to assist you.
Got it, thank you.
AD1955 SPI transmit is OK.
If use software ctrl ad1955, need wm8805 send what data to ad1955? ( sample rate and so on ).
Or need monitor what data of wm8805?
MCLK come from wm8805 ?
I am not sure what you are asking. Do you have a schematic that you can share with me, so that I can review your project so far? Thanks.
Pls. give me you email, I will send sch-pdf to you.
I will start a private discussion for this thread.
1. 192khz how to set?
reg_1 256fs/512fs/768fs, but no 64fs/128fs/192fs.
the dac device work good at 44.1/48/96/176.4, but not work 192k.
2. reg_0 de-emphasis, reg_1 zero flag polarity, how to use, I have not set it.
Allowable Master Clock Frequencies ( f
64 96 128 192 256 384 512 768
Sample Rate (kHz)
48 kHz (INT 8×) Mode •••32, 44.1, 48
96 kHz (INT 4×) Mode ••• 88.2, 96
192 kHz (INT 2×) Mode ••• 176.4, 192
External Filter Mode
S)Nominal Input Sample Rate
Input Sample Rate
(to External Filter) (kHz)
8 × f
•••32, 44.1, 48
4 × f
••• 88.2, 96
2 × f
••• 176.4, 192
The MCLK multiplier should be set using the base rate of the IC; for Fs = 192 kHz, base rate is 48 kHz. 256fs would require an MCLK of 12.288 MHz, 512fs would require an MCLK of 24.576 MHz, and 768fs would require an MCLK of 36.864 MHz. Once this has been defined correctly, you set the sample rate to INT 2x for 192 kHz.
De-emphasis is described on the front page of the datasheet:
The AD1955 is fully compatible with all known DVD audio formats including 192 kHz as well as 96 kHz sample frequencies and 24 bits. It is also backward compatible by supporting 50 μs/ 15 μs digital de-emphasis intended for “redbook” compact discs, as well as de-emphasis at 32 kHz and 48 kHz sample rates.
Zero Detection is described on Page 13 of the datasheet:
When the AD1955 detects that the audio input data is continuously zero during 1024 LRCLK periods in PCM Mode or 8192 LRCLK periods in 8fS External Digital Filter Mode, ZEROL (Pin 21) or ZEROR (Pin 20) is set to active. When the AD1955 is in SACD Mode, it will detect an SACD mute pattern. If the input bit stream shows a mute pattern for about 22 ms, the AD1955 will set ZEROL (Pin 21) or ZEROR (Pin 20) to active. The outputs can be set to active high or low using Control Register 1, Bit 8.
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