s3c2410a Samsung Semiconductor, Inc., s3c2410a Datasheet - Page 452

• Manufacturer Part Number: s3c2410a
• Description: 16/32-bit Risc Arm Microprocessor
• Manufacturer: Samsung Semiconductor, Inc.

MMC/SD/SDIO HOST CONTROLLER
S3C2410A
SDI Data/Busy Timer Register
SDI data/ busy timer register has 16-bit counter. In case of 25MHz operation, the countable maximum time is 2.6ms
(40ns * 0x10000). But, some cards have very long access time (TAAC), their TAAC are up to 100ms. In this case the
SDI generates data timeout error state. To solve this problem follow the below flow chart.
Start
Read
(multil or single block)
Yes
25MHz
Is timeout occurs?
25MHz or 600KHz ?
Send stop command
No
Send stop command if
Change SDI clock to
600KHz
multi block
600KHz
Retry
Change SDI clock to
Real-timeout error
25MHz if 600KHz
Return
Return error
19-16