mx53 cpsi 时钟源修改Low-Frequency Reference Clock (32.768 KHz)

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mx53 cpsi 时钟源修改Low-Frequency Reference Clock (32.768 KHz)

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pensive
Contributor I

依据手册设置CSPI_PERIODREG=0x8000,但实际测量出来时钟信号经过换算仍然是66M,请问怎么能修改cspi时钟源?需要将时钟源降低到400HZ。

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igorpadykov
NXP Employee
NXP Employee

Hi peng

CSPI_PERIODREG is used for clock of pause beteween data transfers.

CSPI data transfer clocks are defined using ECSPIx_CONREG dividers

and CCM ECSPI_CLK_ROOT, check Figure 18-2. CCM Clock Tree

i.MX53 Reference Manual (rev.2.1  6/2012)

http://www.freescale.com/files/32bit/doc/ref_manual/iMX53RM.pdf

Best regards

chip

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571 Views
pensive
Contributor I

怎么修改cspi时钟源,我发现ecspi1,ecspi2时钟源为12M,cspi时钟源为66M,按照手册的 Figure 18-2. CCM Clock Tree i.MX53 Reference Manual (rev.2.1  6/2012),这个图表中只有ecpsi_clk_root,没有CSPI部分,而且其他部分对CSPI时钟源的描述很少,无法修改。按照ECSPI1的方式进行修改仍然无效。

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igorpadykov
NXP Employee
NXP Employee

Hi peng

plase check sect.19.6.3 Control Register (CSPI_CONREG):

divider "DATA RATE".

Best regards

chip

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