TAS5717 Audio Amplifier some registers readback is not the value written into

madoka

Other Parts Discussed in Thread: TAS5707

"X00 6C",
"X01 C1",
"X03 80",
"X04 05",
"X05 00",
"X07 01 10",
"X08 01 10",
"X09 01 10",
"X0A 01 10",
"X0E F1",
"X11 77",
"X12 7F",
"X13 77",
"X14 7F",
"X1A 0F",
"X1B 00",
"X1C 07",
"X20 00 01 77 72",
"X21 00 00 43 03",
"X25 01 02 13 45",
"X26 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X27 00 7E ED 70 15 02 25 20 00 7E ED 70 00 FD C9 79 02 82 13 B9",
"X28 00 7F 32 58 0F 04 36 1B 00 7D 21 DB 00 FB C9 E5 0F 83 AB CD",
"X29 00 7F 77 F6 0F 07 50 35 00 7B 5D 2F 00 F8 AF CB 0F 85 2A DB",
"X2A 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X2B 00 DC 3F 74 0F 3B 93 F4 00 45 90 CF 00 3D E6 A7 0F E4 B5 22",
"X2C 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X2D 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X2E 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X2F 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X30 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X31 00 7E ED 70 0F 02 25 20 00 7E ED 70 00 FD C9 79 0F 82 13 B9",
"X32 00 7F 32 58 0F 04 36 1B 00 7D 21 DB 00 FB C9 E5 0F 83 AB CD",
"X33 00 7F 77 F6 0F 07 50 35 00 7B 5D 2F 00 F8 AF CB 0F 85 2A DB",
"X34 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X35 00 DC 3F 74 0F 3B 93 F4 00 45 90 CF 00 3D E6 A7 0F E4 B5 22",
"X36 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X37 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X38 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X39 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"X3B 00 20 00 00 00 40 00 00",
"X3C 00 00 10 00 FF FF FF FD",
"X3E 00 20 00 00 00 40 00 00"
"X3F 00 08 00 00 FF F8 00 00"
"X40 08 00 00 00"
"X43 00 74 00 00"
"X46 00 02 00 20"
"X4F 00 00 00 06"
"X50 00 00 00 10"
"X51 00 80 00 00 00 00 00 00"
"X52 00 80 00 00 00 00 00 00"
"X56 00 40 00 00",
"X57 00 06 00 00",

After I wrote the register X27 - X35, the 5th and 17th elements were written as 0x0F, 
but for some reason, I read back to check the register value. it read 0x03. 

For register X50, I wrote 00 00 00 10 in the register. I read 0F 70 80 10. 

Why is reading the wrong value???

I wrote 0x00 to X1B register. which mentioned in one thread: 
http://e2e.ti.com/support/amplifiers/audio_amplifiers/f/6/t/283172.aspx

By the way, I only connect the power of the board. there is no speaker connected yet. 

Thanks in advance.

over 10 years ago

0 madoka over 10 years ago

Intellectual 775 points

I understand why 0x0F replaced by 0x03 in register X27 - X35. it is because access to unused bits.

However, I still do not understand why register X50 vaule changed to 0x0F 0x70 0x80 0x10. this is initialization value. but the datasheet shown the default value is all 0x00

I also looked at TAS5707 datasheet. X50 register can configure as 0x0F 0x70 0x80 0x10.

anyone knows?

Thanks

0 Don Dapkus over 10 years ago in reply to madoka

TI__Guru**** 189399 points

Hi, madoka,

it is possible that the default values in the data sheet have an error. Also, some registers have a don't care which can result in different data. What are you trying to do?

0 madoka over 10 years ago in reply to Don Dapkus

Intellectual 775 points

Don,

Thank you for replying.

I am doing run time diagnostic, basically to make sure the configuration bytes written in are same during regularly check(read back).

if X50 register bit8 - 31 are always read to be 0x0F 0x70 0x80, then it will be fine for diagnostic.

Could you help me to find out the right default value of X50 register?

Thank you very much

0 Roman Wang over 10 years ago in reply to madoka

TI__Intellectual 2145 points

Hi madoka,

the bit 8-31 of 0X50 are reversed, just ignore the value of that. and when read it awalys 0F 70 80 XX even if you have writen into. I think just pay attention to bit7 and bit4.

Best Regards,

RomanWang

0 madoka over 10 years ago in reply to Roman Wang

Intellectual 775 points

Roman,

perfect!

Thank you so much

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TAS5717 Audio Amplifier some registers readback is not the value written into