From the title, the system likely contains:
This specific revision of the user guide includes three known silicon bugs: sd3.0-host-ahb-emmc4.4-usersguide-ver5.9-jan11-10.pdf
// Set AHB clock to 66 MHz, divide by 2 for host core (33 MHz) write_register(SDCTL, (1 << 8) | 0x01); // Soft reset | Clock div 2 delay_ms(10); From the title, the system likely contains: This
| Feature | SD 3.0 Host Mode | eMMC 4.4 Mode | | :--- | :--- | :--- | | | Class 0, 2, 4, 6 (ACMD41) | Class 0, 1, 2, 3, 4, 5, 6 (CMD1) | | Initialization | ACMD41 with OCR | CMD1 with OCR | | Voltage | 2.7V – 3.6V | 2.7V – 3.6V or 1.8V (Dual) | | Data Transfer | High Speed (50 MHz) / SDR104 (208 MHz) | Legacy (26 MHz) / High Speed (52 MHz) / DDR (50 MHz) | | Bus Width | 1-bit or 4-bit | 1-bit, 4-bit, or 8-bit | From the title