ESP32-C6 SDIO接口, 4线通讯异常

[qinyunti]

Answers checklist.

• I have read the documentation ESP-AT Programming Guide and the issue is not addressed there.
• I have used the latest released firmware or have updated my ESP-AT branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

ESP32-C6 SDIO接口,
配置如下
1MHZ速度, 没有使能HS，SDIO时序配置如下，外部硬件上拉
sdio_slave_config_t config = { .sending_mode = SDIO_SLAVE_SEND_STREAM, .send_queue_size = CONFIG_AT_SDIO_QUEUE_SIZE, .recv_buffer_size = CONFIG_AT_SDIO_BLOCK_SIZE, .flags = 0, .timing = SDIO_SLAVE_TIMING_NSEND_PSAMPLE, .event_cb = s_event_cb, };
1线时通讯正常，4线时HOST报RESP和DATA的CRC错误，
逻辑分析仪抓包，发现4线时RESP的CRC7丢掉了一位，应该是0x2D的实际是0x5B，如图
看起来是使能4线后，C6发送CRC7时丢失了最开始的1个bit。

[qinyunti]

测试发现和4线没关系，单线时也有，基本都是CRC区域丢掉了一个bit，导致host crc错误。

[Jacques-Zhao]

这个问题就是 SDIO 时序问题， 首先需要保证 SDIO 通信的IO都有加上拉 https://docs.espressif.com/projects/esp-idf/zh_CN/latest/esp32c6/api-reference/peripherals/sdio_slave.html。
然后不知道你们当前怎么连接的，如果是杜邦线，需要保证线小于 10cm，而且需要接多个 GND，而 4bit的话，基本上PCB走线是必须的