4bit不是应该快很多吗，但是实际并没有快多少，600多K的文件，要700ms才能读完。
这是1bit时的日志：
- I (0) cpu_start: App cpu up.
- I (1218) spiram: SPI SRAM memory test OK
- I (1227) cpu_start: Pro cpu start user code
- I (1227) cpu_start: cpu freq: 240000000
- I (1227) cpu_start: Application information:
- I (1230) cpu_start: Project name: sd_card
- I (1235) cpu_start: App version: ac75c64-dirty
- I (1241) cpu_start: Compile time: Apr 6 2022 14:41:49
- I (1247) cpu_start: ELF file SHA256: 9c75e896892f3e6c...
- I (1253) cpu_start: ESP-IDF: v4.4-dirty
- I (1258) heap_init: Initializing. RAM available for dynamic allocation:
- I (1266) heap_init: At 3FC951D8 len 0004AE28 (299 KiB): D/IRAM
- I (1272) heap_init: At 3FCE0000 len 0000EE34 (59 KiB): STACK/DRAM
- I (1279) heap_init: At 3FCF0000 len 00008000 (32 KiB): DRAM
- I (1285) heap_init: At 600FE000 len 00002000 (8 KiB): RTCRAM
- I (1292) spiram: Adding pool of 8192K of external SPI memory to heap allocator
- I (1300) spi_flash: detected chip: gd
- I (1304) spi_flash: flash io: dio
- I (1308) sleep: Configure to isolate all GPIO pins in sleep state
- I (1315) sleep: Enable automatic switching of GPIO sleep configuration
- I (1322) cpu_start: Starting scheduler on PRO CPU.
- I (0) cpu_start: Starting scheduler on APP CPU.
- I (1337) spiram: Reserving pool of 32K of internal memory for DMA/internal allocations
- I (1346) example: Initializing SD card
- I (1350) example: Using SDMMC peripheral
- I (1355) example: Mounting filesystem
- I (1359) gpio: GPIO[8| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
- I (1369) gpio: GPIO[10| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
- I (1378) gpio: GPIO[6| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
- I (1435) example: Filesystem mounted
- Name: SD
- Type: SDSC
- Speed: 20 MHz
- Size: 121MB
- I (1436) example: Opening file /sdcard/hello.txt
- I (1446) example: File written
- I (1450) example: Renaming file /sdcard/hello.txt to /sdcard/foo.txt
- I (1452) example: Reading file /sdcard/foo.txt
- I (1456) example: Read from file: 'Hello SD !'
- I (1556) example: list: /,open succeed
- I (1557) example: file: 2.MJP , size: 622178 , fattrib: 32
- I (1557) example: file: FOO.TXT , size: 13 , fattrib: 32
- I (1562) example: free_heap_size = 8082979
- I (1567) example: free_heap_size = 8078883
- I (2279) example: read 622178 bytes in 707 ms
- I (2280) example: free_heap_size = 8082979
- I (2280) example: Card unmounted
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这是4bit时的日志：
Code: [Select all] [Expand/Collapse]
- I (0) cpu_start: App cpu up.
- I (1218) spiram: SPI SRAM memory test OK
- I (1227) cpu_start: Pro cpu start user code
- I (1227) cpu_start: cpu freq: 240000000
- I (1227) cpu_start: Application information:
- I (1230) cpu_start: Project name: sd_card
- I (1235) cpu_start: App version: ac75c64-dirty
- I (1241) cpu_start: Compile time: Apr 6 2022 14:41:49
- I (1247) cpu_start: ELF file SHA256: ca6d01d26a856673...
- I (1253) cpu_start: ESP-IDF: v4.4-dirty
- I (1258) heap_init: Initializing. RAM available for dynamic allocation:
- I (1266) heap_init: At 3FC951D8 len 0004AE28 (299 KiB): D/IRAM
- I (1272) heap_init: At 3FCE0000 len 0000EE34 (59 KiB): STACK/DRAM
- I (1279) heap_init: At 3FCF0000 len 00008000 (32 KiB): DRAM
- I (1285) heap_init: At 600FE000 len 00002000 (8 KiB): RTCRAM
- I (1292) spiram: Adding pool of 8192K of external SPI memory to heap allocator
- I (1300) spi_flash: detected chip: gd
- I (1304) spi_flash: flash io: dio
- I (1308) sleep: Configure to isolate all GPIO pins in sleep state
- I (1315) sleep: Enable automatic switching of GPIO sleep configuration
- I (1322) cpu_start: Starting scheduler on PRO CPU.
- I (0) cpu_start: Starting scheduler on APP CPU.
- I (1337) spiram: Reserving pool of 32K of internal memory for DMA/internal allocations
- I (1346) example: Initializing SD card
- I (1350) example: Using SDMMC peripheral
- I (1355) example: Mounting filesystem
- I (1359) gpio: GPIO[8| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
- I (1369) gpio: GPIO[10| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
- I (1378) gpio: GPIO[6| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
- I (1387) gpio: GPIO[7| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
- I (1396) gpio: GPIO[12| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
- I (1406) gpio: GPIO[5| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
- I (1463) example: Filesystem mounted
- Name: SD
- Type: SDSC
- Speed: 20 MHz
- Size: 121MB
- I (1464) example: Opening file /sdcard/hello.txt
- I (1474) example: File written
- I (1530) example: Renaming file /sdcard/hello.txt to /sdcard/foo.txt
- I (1532) example: Reading file /sdcard/foo.txt
- I (1533) example: Read from file: 'Hello SD !'
- I (1633) example: list: /,open succeed
- I (1633) example: file: 2.MJP , size: 622178 , fattrib: 32
- I (1633) example: file: FOO.TXT , size: 13 , fattrib: 32
- I (1639) example: free_heap_size = 8082979
- I (1643) example: free_heap_size = 8078883
- I (2356) example: read 622178 bytes in 707 ms
- I (2356) example: free_heap_size = 8082979
- I (2357) example: Card unmounted
