RT1052的SDRAM的IPTXDAT寄存器的配置问题

FromCH0 — Mon, 13 Apr 2026 07:37:19 GMT

NXP技术支持：

您好！

以下是NXP官方RT1052的SDK中的.ini文件中的SDRAM初始化部分：

FUNC void _sdr_Init(void)
{
// Config IOMUX
_WDWORD(0x401F8014, 0x00000000);
_WDWORD(0x401F8018, 0x00000000);
_WDWORD(0x401F801C, 0x00000000);
_WDWORD(0x401F8020, 0x00000000);
_WDWORD(0x401F8024, 0x00000000);
_WDWORD(0x401F8028, 0x00000000);
_WDWORD(0x401F802C, 0x00000000);
_WDWORD(0x401F8030, 0x00000000);
_WDWORD(0x401F8034, 0x00000000);
_WDWORD(0x401F8038, 0x00000000);
_WDWORD(0x401F803C, 0x00000000);
_WDWORD(0x401F8040, 0x00000000);
_WDWORD(0x401F8044, 0x00000000);
_WDWORD(0x401F8048, 0x00000000);
_WDWORD(0x401F804C, 0x00000000);
_WDWORD(0x401F8050, 0x00000000);
_WDWORD(0x401F8054, 0x00000000);
_WDWORD(0x401F8058, 0x00000000);
_WDWORD(0x401F805C, 0x00000000);
_WDWORD(0x401F8060, 0x00000000);
_WDWORD(0x401F8064, 0x00000000);
_WDWORD(0x401F8068, 0x00000000);
_WDWORD(0x401F806C, 0x00000000);
_WDWORD(0x401F8070, 0x00000000);
_WDWORD(0x401F8074, 0x00000000);
_WDWORD(0x401F8078, 0x00000000);
_WDWORD(0x401F807C, 0x00000000);
_WDWORD(0x401F8080, 0x00000000);
_WDWORD(0x401F8084, 0x00000000);
_WDWORD(0x401F8088, 0x00000000);
_WDWORD(0x401F808C, 0x00000000);
_WDWORD(0x401F8090, 0x00000000);
_WDWORD(0x401F8094, 0x00000000);
_WDWORD(0x401F8098, 0x00000000);
_WDWORD(0x401F809C, 0x00000000);
_WDWORD(0x401F80A0, 0x00000000);
_WDWORD(0x401F80A4, 0x00000000);
_WDWORD(0x401F80A8, 0x00000000);
_WDWORD(0x401F80AC, 0x00000000);
_WDWORD(0x401F80B0, 0x00000010); // EMC_39, DQS PIN, enable SION

// PAD ctrl
// drive strength = 0x7 to increase drive strength
// otherwise the data7 bit may fail.
_WDWORD(0x401F8204, 0x000110F9);
_WDWORD(0x401F8208, 0x000110F9);
_WDWORD(0x401F820C, 0x000110F9);
_WDWORD(0x401F8210, 0x000110F9);
_WDWORD(0x401F8214, 0x000110F9);
_WDWORD(0x401F8218, 0x000110F9);
_WDWORD(0x401F821C, 0x000110F9);
_WDWORD(0x401F8220, 0x000110F9);
_WDWORD(0x401F8224, 0x000110F9);
_WDWORD(0x401F8228, 0x000110F9);
_WDWORD(0x401F822C, 0x000110F9);
_WDWORD(0x401F8230, 0x000110F9);
_WDWORD(0x401F8234, 0x000110F9);
_WDWORD(0x401F8238, 0x000110F9);
_WDWORD(0x401F823C, 0x000110F9);
_WDWORD(0x401F8240, 0x000110F9);
_WDWORD(0x401F8244, 0x000110F9);
_WDWORD(0x401F8248, 0x000110F9);
_WDWORD(0x401F824C, 0x000110F9);
_WDWORD(0x401F8250, 0x000110F9);
_WDWORD(0x401F8254, 0x000110F9);
_WDWORD(0x401F8258, 0x000110F9);
_WDWORD(0x401F825C, 0x000110F9);
_WDWORD(0x401F8260, 0x000110F9);
_WDWORD(0x401F8264, 0x000110F9);
_WDWORD(0x401F8268, 0x000110F9);
_WDWORD(0x401F826C, 0x000110F9);
_WDWORD(0x401F8270, 0x000110F9);
_WDWORD(0x401F8274, 0x000110F9);
_WDWORD(0x401F8278, 0x000110F9);
_WDWORD(0x401F827C, 0x000110F9);
_WDWORD(0x401F8280, 0x000110F9);
_WDWORD(0x401F8284, 0x000110F9);
_WDWORD(0x401F8288, 0x000110F9);
_WDWORD(0x401F828C, 0x000110F9);
_WDWORD(0x401F8290, 0x000110F9);
_WDWORD(0x401F8294, 0x000110F9);
_WDWORD(0x401F8298, 0x000110F9);
_WDWORD(0x401F829C, 0x000110F9);
_WDWORD(0x401F82A0, 0x000110F9);

// Config SDR Controller Registers/
_WDWORD(0x402F0000,0x10000004); // MCR
_WDWORD(0x402F0008,0x00000081); // BMCR0
_WDWORD(0x402F000C,0x00000081); // BMCR1
_WDWORD(0x402F0010,0x8000001B); // BR0, 32MB

_WDWORD(0x402F0040,0x00000F07); // SDRAMCR0
_WDWORD(0x402F0044,0x00652922); // SDRAMCR1
_WDWORD(0x402F0048,0x00010920); // SDRAMCR2
_WDWORD(0x402F004C,0x50210A08); // SDRAMCR3

_WDWORD(0x402F0090,0x80000000); // IPCR0
_WDWORD(0x402F0094,0x00000002); // IPCR1
_WDWORD(0x402F0098,0x00000000); // IPCR2

_WDWORD(0x402F009C,0xA55A000F); // IPCMD, SD_CC_IPREA
SDRAM_WaitIpCmdDone();
_WDWORD(0x402F009C,0xA55A000C); // SD_CC_IAF
SDRAM_WaitIpCmdDone();
_WDWORD(0x402F009C,0xA55A000C); // SD_CC_IAF
SDRAM_WaitIpCmdDone();
_WDWORD(0x402F00A0,0x00000030); // IPTXDAT
_WDWORD(0x402F009C,0xA55A000A); // SD_CC_IMS
SDRAM_WaitIpCmdDone();
_WDWORD(0x402F004C,0x08080A01 ); // enable sdram self refresh again after initialization done.
}

我查了官方的RM（参考手册），然后，还是不理解“_WDWORD(0x402F00A0,0x00000030); // IPTXDAT”这个语句中，为何要把0x402F00A0这一寄存器的数据配置成x00000030。事实上，RM中，这部分描述很少。网上有种说法，说这是为了配置成“0011 = CAS Latency = 3个时钟周期”，对吗？

谢谢！

Re: RT1052的SDRAM的IPTXDAT寄存器的配置问题

mayliu1 — Fri, 17 Apr 2026 08:13:11 GMT

Hi @FromCH0 ,

Thank you so much for your interest in our products and for using our community.

"_WDWORD(0x402F00A0,0x00000030); // IPTXDAT

_WDWORD(0x402F009C,0xA55A000A); // SD_CC_IMS" is used to write the mode register inside the SDRAM memory.

To init one SDRAM, we need to configure the mode register inside the SDRAM memory, below is an example of mode register in the SDRAM. It configured Latency mode, burst type, burst length and etc..

So 0x00000030 corresponds to the configuration value of the mode register inside the SDRAM. It configured the CAS latency to 3 and burst length to 1.

Wish it helps you

Best Regards

May Liu

Re: RT1052的SDRAM的IPTXDAT寄存器的配置问题

FromCH0 — Fri, 17 Apr 2026 08:45:45 GMT

感谢！

topic Re: RT1052的SDRAM的IPTXDAT寄存器的配置问题 in i.MX RT Crossover MCUs

RT1052的SDRAM的IPTXDAT寄存器的配置问题

Re: RT1052的SDRAM的IPTXDAT寄存器的配置问题

Re: RT1052的SDRAM的IPTXDAT寄存器的配置问题