I2S Transceiver

[Johann Glaser]

Hi!

For my TriCore µC system I'm planning to add a PCB with an audio CODEC.
All codecs I found have an I2S (note: I2S, not I2C) interface to tell them
the digital data.

My TriCore (TC1775) doesn't have a I2S Interface, I'm searching for an IC
which can be attached to a normal microprocessor bus. This should then
generate the I2S output. The µC then has at a certain address region some
registers and possibly a bit of (e.g. FIFO) memory. This is in the I2S IC.
The firmware then writes the audio data via the bus to the I2S IC.

Could you please point me to such an IC? I couldn't find any despite I
searched hard.

Thanks in advance
Hansi

 

[Mike Harrison]

Hi!

For my TriCore µC system I'm planning to add a PCB with an audio CODEC.
All codecs I found have an I2S (note: I2S, not I2C) interface to tell them
the digital data.

My TriCore (TC1775) doesn't have a I2S Interface, I'm searching for an IC
which can be attached to a normal microprocessor bus. This should then
generate the I2S output. The µC then has at a certain address region some
registers and possibly a bit of (e.g. FIFO) memory. This is in the I2S IC.
The firmware then writes the audio data via the bus to the I2S IC.

Could you please point me to such an IC? I couldn't find any despite I
searched hard.

Thanks in advance
Hansi

I doubt you will find an IC like this as most I2S systems generate it from an all-in-one controller
- e.g. a CD player decoder etc.

You will probably need to implement your own solution in a small FPGA or using discrete logic.
You _may_ be able to do it using a fast microcontroller (PIC,AVR etc.), as the SPI bus can usually
be made to look like I2S - I've done this in the past on a PIC, using the PWM peripheral to generate
LRCLK, and the SPI to generate the data, although this was only at 22KHz sample-rate, but the PIC
was only running at 4MHz, so a 20MHz PIC (or 40MHz PIC18 series) could probably do it reasonably
well, as long as your required FIFO size fitted the PIC's RAM. The higher-end PICs alos have a CPU
bus interface (PSP) which may help.

 

[petrus bitbyter]

I doubt you will find an IC like this as most I2S systems generate it from an all-in-one controller
- e.g. a CD player decoder etc.

You will probably need to implement your own solution in a small FPGA or using discrete logic.
You _may_ be able to do it using a fast microcontroller (PIC,AVR etc.), as the SPI bus can usually
be made to look like I2S - I've done this in the past on a PIC, using the PWM peripheral to generate
LRCLK, and the SPI to generate the data, although this was only at 22KHz sample-rate, but the PIC
was only running at 4MHz, so a 20MHz PIC (or 40MHz PIC18 series) could probably do it reasonably
well, as long as your required FIFO size fitted the PIC's RAM. The

higher-end PICs alos have a CPU

bus interface (PSP) which may help.

I have no solution but a related question: Where to find the I2S
specifications?

petrus.

 

[Iwo Mergler]

an all-in-one controller


using discrete logic.


the SPI bus can usually


PWM peripheral to generate


sample-rate, but the PIC


probably do it reasonably


higher-end PICs alos have a CPU


I have no solution but a related question: Where to find the I2S
specifications?

petrus.

http://www.semiconductors.philips.com/acrobat/various/I2SBUS.pdf

 

[Iwo Mergler]

Hi!

For my TriCore µC system I'm planning to add a PCB with an audio CODEC.
All codecs I found have an I2S (note: I2S, not I2C) interface to tell them
the digital data.

My TriCore (TC1775) doesn't have a I2S Interface, I'm searching for an IC
which can be attached to a normal microprocessor bus. This should then
generate the I2S output. The µC then has at a certain address region some
registers and possibly a bit of (e.g. FIFO) memory. This is in the I2S IC.
The firmware then writes the audio data via the bus to the I2S IC.

Could you please point me to such an IC? I couldn't find any despite I
searched hard.

Thanks in advance
Hansi

What you need is a synchronous serial port capable of doing
some 1.5 MBits/sec. If the port doesn't support the I2S frame
signal you could generate is with some TTL grade devices (16 bit
counter).


If you're comfortable with CPLDs or FPGAs use them. It's a good
thing to have on any processor board.

Kind regards,

Iwo

 

[petrus bitbyter]

http://www.semiconductors.philips.com/acrobat/various/I2SBUS.pdf

Thanks.

petrus