SD卡：cmd 17（读取单个块）响应始终为0x01

我试图连接一个微型SD卡到PIC32控制器。PCB是自己设计的，不是某种标准的开发板。目前，我正在使用SPI协议来与卡进行通信。（在不久的将来，我将使用正确的引脚使用真正的SPI，但现在我必须使用这个解决方案）。长话短说：我能够初始化卡并为所有命令获得正确的响应，但是当我尝试发布CMD 17命令时，它响应0x01（空闲）而不是0x00（就绪），并且任何后续读取所有返回0xFF。预期的令牌0xFE永远不会到来。我已经尝试了很多不同的领域作为CMD 17的论证，但这并没有什么区别。这些是初始化的命令和响应：除了最后一个之外，它们看起来都很好。（BTW，我总是使用正确的CRC，即使我知道它不是必要的）。这让我觉得我的设置基本上是正确的。卡是3.3V供电的。当访问卡时，电压不会下降。除了CLK外，所有的线路都有100K的上拉电阻。（BIT）时钟频率约为145千赫。这对读命令有什么影响吗？我相信它必须低于400千赫在初始化。但是对阅读和写作还有什么要求吗？我还没有找到。CMD 17没有给出正确答案的原因是什么？



      以下为原文

    I'm trying to connect a micro-SD card to a PIC32 controller. The PCB is own design, not some kind of standard development board. At the moment I'm bitbanging the SPI protocol to communicate with the card. (In the near future I will use the proper pins to use real SPI, but for now I have to use this solution). Long story short: I am able to initialise the card and get correct responses for all commands, but when I try to issue the cmd 17 command, it responds with 0x01 (idle) instead of 0x00 (ready) and any subsequent reads all return 0xFF. The expected token 0xFE never comes. I've tried a lot of different sectors as argument for cmd 17, but that doesn't make a difference.

These are the commands and responses for initialisation:
>> (0) 40 00 00 00 00 95
<< (0) 01

>> (8) 48 00 00 01 AA 87
<< (8) 01 00 00 01 AA

>> (55) 77 00 00 00 00 65
<< (55) 01

>> (41) 69 40 00 00 00 77
<< (41) 01

>> (58) 7A 00 00 00 00 FD
<< (58) 01 40 FF 80 00

>> (16) 50 00 00 02 00 15
<< (16) 01

>> (17) 51 00 00 00 00 55
<< (17) 01
They all look good to me, except the last one. (BTW, I'm always using the correct CRC even though I'm aware that it's not neccesary). This makes me think that my setup is basically correct.

The card is powered with 3.3V. The voltage doesn't drop when accessing the card. All lines excepct clk have a 100k pullup resistor.

The (bit-banged) clock frequency is about 145 kHz. Could this have any influence on the read command? I believe it has to be below 400 kHz at initialisation. But are there any further requirements for reading/writing? I haven't found any.

What could be the reason for cmd 17 not giving the correct response?