RT 1176 FlexSPI RW frequency DQS

[yosri_c]

hi,

we have a question regarding the flash NOR RW freq .

we currenty working on a custom board using the RT1176 , we are implementig a  flashloader a bootsel and a bootloader as we want to boot from  IS25LP128 SERIAL FLASH MEMORY WITH 133MHZ MULTI I/O SPI & QUAD I/O 

so the boot flow is perfect when running on 60Mhz serialClkFreq , but we need to raise that to 133Mhz 

after Refernce manual lookup , we found that we need a to mux a FLEXSPI DQS pin and change the sampling to  readSampleClksrc= kFlexSPIReadSampleClk_LoopbackFromDqsPad .

but when looking for pin mux options we found 3 choices basicaly AD_17 ,  SD_B2_05 and EMC_B2_18 

we tried three of them and none worked (no boot) 

is there anything else we're missing ! 

thank you 

Yosri 

#i.MX-RT1176  

[yosri_c]

hi @HangZhang ,

okay thank you for the reply ,

we're just  conserned and want to know the use of the PIN GPIO_EMC_B2_18 is it deprecated and doesn't support DQS functionality anymore ? 

because we still have it in the refernce manual as a DQS pin .

Thank you so much indeed for clarifying this 

[HangZhang · Accepted solution]

Hi @yosri_c 

Not all FlexSPI Pinmux combinations can be used to connect to serial NOR Flash for boot.
About boot pin, please refer to the system boot chapter in the RM manual.

Hope this will help you.

BR

Hang

[yosri_c]

hi ,

i read the section and that's why i asked , the GPIO_EMC_B2_18 pin was used in a previous RM as FlexSPI_DQS_A pin , and then i read about it in another thread that it will be depracated !

my question was , does  this pin support the DQS function  or not anymore 

( RT1176 - flexSPI DQS connection for max R/W speed - NXP Community )

Thank you 

[HangZhang]

Hi @yosri_c

According to the rt1170 RM, it can be used as FLEXSPI1_A_DQS pin.

But for Boot, it can not be used as DQS pin.

Hope this will help you.

BR

Hang

[HangZhang]

Hi @yosri_c 

When the transmission rate is relatively high, in order to transmit data more accurately, DQS is provided by flash.

So you can try to config

config.rxSampleClock = kFLEXSPI_ReadSampleClkExternalInputFromDqsPad.

And config the pin mux that you mentioned.

Hope this will help you.

BR

Hang

[yosri_c]

hi, 

thank you for the answer . as i mentionned we already changed the sampling config to kFLEXSPI_ReadSampleClkExternalInputFromDqsPad.

we changed the  .serialClkFreq = kFlexSpiSerialClk_133MHz 

we muxed the pin 

IOMUXC_SetPinMux(

         IOMUXC_GPIO_AD_17_FLEXSPI1_A_DQS,   // GPIO_EMC_B2_18 is configured as FLEXSPI1_A_DQS

       1U);                                    //  Software Input On Field: Force input path of pad GPIO_EMC_B2_18

   IOMUXC_SetPinConfig(

       IOMUXC_GPIO_AD_17_FLEXSPI1_A_DQS,  //  GPIO_EMC_B2_18 PAD functional properties :

       0x07U);                           

but still we couldn't boot 

[HangZhang]

Hi @yosri_c 

Are you using the Primary Pin Group or the Secondary Pin Group？

According the i.MX RT1170  Reference Manual. For the secondary pin group, the Maximum Flash
frequency supported on this port is 100MHz.

.

And have you chosen this frequency?

Hope this will help you.

BR

Hang