SSI reads back what was written to TXD

[dirkschäfer]

Hello,

I use the SSI1 with AUDMUX1 and AUDMUX4 in a simple way.

// bith PINs to ALT3

m_muxAud4TXD.SetAddr( 0x020E0050);

m_muxAud4TXD.SetValue( 3);

m_muxAud4RXD.SetAddr( 0x020E0054);

m_muxAud4RXD.SetValue(3);

// AUDMUX1 gets all clocks and syncs from SSI1

m_audm1_ptcr.SetValue( 0);

m_audm1_pdcr.SetValue( (3<<13) );

// AUDMUX4 gets all needed from AUDMUX1

m_audm4_ptcr.SetValue( (1<<31) + (1<<26) + (1<<21) + (1<<16) );

m_audm4_pdcr.SetValue( 0);

// enable recv, transmit and SSI1

m_ssi1cr.SetValue( (1<<2) + (1<<1) + (1<<0) );

// fifo 0 enable, frame and clock dir internal

m_ssi1stcr.SetValue( (1<<7) + (1<<6) + (1<<5) );

// divide by 2, prescaler, 24bits, modulus

m_ssi1stccr.SetValue( (1<<18) + (1<<17) + (11<<13) + 0x02);

m_ssi1srcr.SetValue( (1<<7) + (1<<6) + (1<<5) );

m_ssi1srccr.SetValue( (1<<18) + (1<<17) + (11<<13) + 0x02);

// Masks to send

g_aSending[0]= 0xCCCCCC00;

g_aSending[1]= 0xCCCCCC00;

g_aSending[2]= 0xCCCCFF00;

g_aSending[3]= 0xFFFFFFFF;

g_aSending[4]= 0xFFFFFFFF;

I send whenever ssi1sfcsr&0x00000F00 == 0 and read

if ss1sfcsr&0x0000F000 != 0, amount of both events are the same.

Masks are visible on the oscilloscope.

The return is on PIN RXD.

But I always read the pattern send over TXD. From Recv Fifo 0.

Where is my mistake?

Many thanks for your help.

09.06.2016

Changed

m_audm4_ptcr.SetValue( (1<<31) + (1<<26) + (1<<21) + (8<<17) +  (1<<16) + (8<<12) );

Recv masks have high bit set, manual page 716, no success.

[dirkschäfer · Accepted solution]

Tried all I understood. Solved it by using the SPI5. This one uses same Pads. No luck with SSI.

[dirkschäfer]

Tried one more point

m_audm1_ptcr.SetValue( 0x9CC00800);

m_audm1_pdcr.SetValue( 0x00006000);

m_audm4_ptcr.SetValue( 0x000000800);

m_audm4_pdcr.SetValue( 0x0);

After boot AUDMUX1 is connected to AUDMUX6. Changed the init to 4, with the reset values from the manual.

SSI1 to sync.

Output of the bitmaks on TXD, RXD still always 0. Got tx events in Fifo0 and Rx events in Fifo0.

But I always read 0s.

No way out?

[igorpadykov]

Hi Dirk

one can try attached standalone audio test from i.MX6 sdk baremetal tests,

please check pdf document Chapter 5 Configuring the AUDMUX Driver,

Chapter 32 Configuring the SSI Driver.

Best regards

igor

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