Unable to make ADC conversion using Eqadc-B ANB16,17,18,19 channels

[rahulmankumbare]

Hi,

MCU - MPC5777C

IDE- S32DEv1.2

We are using Eqadc-A & Eqadc-B channels for analog to digital conversion.

We are using channels ANA6,ANA34,ANA35,ANA36 etc and able to convert analog data to digital.

Now we are using,

ANB16/GPI484/ETPUC15/EMIOS24

ANB17/GPI485/ETPUC14/EMIOS25

ANB18/GPI486/ETPUC13/EMIOS26

ANB19/GPI487/ETPUC12/EMIOS27 

But Unabble to make conversion.

Following is our init code.

EQADC_B.CFPR[0].R = 0x00800301; // configure ADC_CR0 Register in buffer 0
EQADC_B.CFPR[0].R = 0x82800301; // configure ADC_CR1 Register in buffer 1

EQADC_B.CFCR0.R = 0x1C101C10;
EQADC_B.CFCR1.R = 0x1C101C10;
EQADC_B.CFCR2.R = 0x1C101C10;
// Wait for Queue Done
while (EQADC_B.FISR[0].B.EOQFX == 0) { } /* Wait for End Of Queue flag */

EQADC_B.FISR[0].R = End_of_Queue_Flag;

EQADC_B.IDCR0.R = 0x33033303;
EQADC_B.IDCR1.R = 0x33033303;

SIU.PCR[ANB16_TO_ADC_INV2_TA].R = PRIM_F | K_IBE; //ANB16/GPI484/ETPUC15/EMIOS24

SIU.PCR[ANB17_TO_ADC_INV2_TB].R = PRIM_F | K_IBE; // ANB17/GPI485/ETPUC14/EMIOS25

SIU.PCR[ANB18_TO_ADC_INV2_TD].R = PRIM_F | K_IBE; // ANB18/GPI486/ETPUC13/EMIOS26

SIU.PCR[ANB19_TO_ADC_INV2_TC].R = PRIM_F | K_IBE; //ANB19/GPI487/ETPUC12/EMIOS27

Please suggest missing or incorrect part.

Thanks.

Rahul.

[davidtosenovjan]

Hi, I have just created example code for this configuration.

It works fine on my side. You can download it here:

https://community.nxp.com/docs/DOC-335394 

Hope it helps

[rahulmankumbare]

Hi,

We have tested the code it is working but we are getting sampling frequency =300KHz.

We want to sample the signal having frequency 50KHz.

The samples that we are getting are not sufficient.

We have set peripheral clock frequency == 96MHz

ADC clock == 24MHz

conversion cycles ==2

So sampling frequency should be 1.5MHz. But practically we are getting 300KHz

We have verified it by giving 50KHz signal input. We are getting 8 samples in 1 cycles of waveform.

PUSH_TO_CFIFO1_B ( B0 |
ADC_REG_VALUE (0x8001) | // enables ADC0 0x8001 == divide by 4 //0x8002 == ADC0/1_CLK_PS divide by 6
ADC_REG_ADDR (ADC0_CR) );

LST == 0 // 0 means 2 cycles for conversion.

How to achieve 1.5 MHz sampling frequency?????

Thanks.

Rahul

[rahulmankumbare]

Thanks.

We will check & update you.

[rahulmankumbare]

Hi David,

We are using eDMA.

We are able to achieve single scan conversion previously.

Now we are trying with eDMA.

But we are missing some configuration.

Please guide us.

Thanks.

Rahul

[rahulmankumbare]

Hi David,

We have not been able to read the adc values using DMA yet.

Can you go through the above snaps of our CQueues.

Thanks.

Rahul