topic Re: i.mx RT1050 LPSPI in i.MX RT Crossover MCUs

i.mx RT1050 LPSPI

christiangradl — Tue, 12 Jun 2018 12:00:29 GMT

Hi,

wthats the max. clock freq of the lpspi. in the manual i found

fperiph / 2

in note 1 there stands

fperiph = 60 MHz, maximum frequency of operation is 30 MHz

but in the RM table 18-4 there stands

LPSPI_CLK_ROOT 120 MHz

what is now the maximum freq for the lpspi clock?

Re: i.mx RT1050 LPSPI

Carlos_Musich — Thu, 14 Jun 2018 21:36:48 GMT

Hi Christian,

in Figure 18-2. Clock Tree - Part 1 you can see that LPSPI_CLK_ROOT has a divisor /4 before output. So that matches with what you say above

LPSPI MAX Freq = fperiph / 2 = LPSPI_CLK_ROOT / 4 = 30 MHz

Regards,
Carlos
NXP Technical Support
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Re: i.mx RT1050 LPSPI

christiangradl — Fri, 15 Jun 2018 04:19:11 GMT

Hi,

i can see is the divisor is before the output, thats right, but the

max LPSPI_CLK_ROOT Freq is 120 MHz (table 18-4). So for my calculation i do not this divisor, because max. LSPI Freq is 120 MHz.

I have an SPI Device that can communicate with 180 MHz via SPI.

In "IMXRT1050IEC.pdf" in table 56 there is a note 1, that says 30 MHz.

Is this an example or the absolute output freq that i.mxrt1050 can do?

Re: i.mx RT1050 LPSPI

christiangradl — Mon, 26 Nov 2018 11:30:11 GMT

Hi,

you wrote LPSI Max Freq is 30 Mhz.
In the datasheet i found that the min data setup time is 18ns => 27,7 Mhz

What is now the correct max. freq for LPSPI

Thanx

Re: i.mx RT1050 LPSPI

wre — Sun, 11 Aug 2019 00:09:32 GMT

Hi,

Not sure if you have your answer yet. In IMXRT1050RM, Rev. 2, 11/2018, Table 13-5 on page 1000, says that LPSPI_CLK_ROOT defaults to 6MHz and has a maximum of 132MHz. (PLL2 / 4, 528 / 4 = 132).