SD卡初始化；acmd41 失败； [英] SD card initialisation; acmd41 fails;
问题描述
我正在尝试初始化 SD 卡，但从未准备好卡.
I'm trying to init sd card and never get card ready.
详情:
有带芯片的开发板，带有 SD Host 控制器和 micro SDHC UHS-1 卡.
There are dev board with a chip with a SD Host controller and micro SDHC UHS-1 card.
我正在遵循的初始化序列:
Init sequence I'm following:
- cmd0:arg
0x00.没关系 cmd8:arg
0x1AA.好的，返回 0x1aa.
- cmd0: arg
0x00. That is fine cmd8: arg
0x1AA. Fine, 0x1aa is returned back.
acmd41:
-- 第一个 cmd55: arg 0x00.很好，响应 0x120 表示设置了app_cmd"标志.
-- 第二个 cmd41: arg 0x5100'0000 (HCS: 1; XPC: 1; S18R: 1 - SDHC/SDXC 支持; 最高性能; 分别切换到 1.8V)响应为 0xff8000.所以这似乎是一个有效的 OCR，支持整个电压范围.
acmd41:
-- first cmd55: arg 0x00. Fine, response 0x120 indicates that 'app_cmd' flag is set.
-- second cmd41: arg 0x5100'0000 (HCS: 1; XPC: 1; S18R: 1 - SDHC/SDXC supported; Maximum performance; Switch to 1.8V respectively)
Response is 0xff8000. So that seems to be a valid OCR, supporting a whole voltages range.
一旦知道卡支持的 OCR，我会再次发送 ACMD41 并设置 OCR:
-- cmd55: arg 0x00.有效的 0x120 响应.
-- cmd41: arg 0x51ff'80000.
在这种情况下，即使 SD 主机控制器没有指示任何错误，如超时或错误的 CRC，我总是从一张卡中获得 0xffff'ffff发送该值.
Once OCR supported by a card is known I send ACMD41 again with a set OCR:
-- cmd55: arg 0x00. valid 0x120 response.
-- cmd41: arg 0x51ff'80000.
In this case I always get 0xffff'ffff from a card which is not a proper respond by any means even though SD Host controller do not indicate any errors like timeout or wrong CRC, so that seems that card indeed sends that value.
重复上述acmd41(cmd55 + cmd41)继续返回相同的响应，cmd55没问题，cmd41为0xffffffff
Repeating described above acmd41 (cmd55 + cmd41) continue to return the same response, cmd55 is fine, cmd41 is 0xffffffff
知道出了什么问题/我遗漏了吗?
Any ideas what is going wrong/I'm missing?
谢谢.
推荐答案
很快，卡片初始化序列就可以了.那是硬件问题.
Shortly, card init sequence is fine. That's a hardware issue.
卡的电源被拧紧，因此卡没有足够的电量来正常工作，但不知何故有足够的电量来发送响应.
Power supplying to a card was screwed, so card didn't have enough power for a proper work but somehow got enough to send a responds.
为了让我尝试的几张卡片变得更有趣:
To make things even more interesting out of a few cards I tried:
- 一张卡根本无法使用
- 初始化失败(如上所述)
- 当试图写入数据时，一个人做了所有事情，但无限期地保持在编程"状态.
谢谢大家:)
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