CRITICALITY

Low

DESCRIPTION

A data time-out (DTO) error interrupt (MMCHS_STAT[20] DTO=0x1) occurs at the end of reading transfer with CMD23. In this case, transfer completed (TC) interrupt (MMCHS_STAT[1] TC=0x1) never occurs.

This bug appears only with following restrictive conditions:

• Use CMD23 (command used to specify number of reading and writing block)
• Block count enable BCE (MMCHS_CMD[1]= 0x0
• ADMA (integrated controller DMA system engine) used
• Reading transfer (writing transfer is not affected)
• Only finite transfer affected. CMD12 (stop infinite transfer command) command are not affected.
• Issue happens with both large block count (>2^16) and small block count (<=2^16)

Note: These conditions are used typically with UHS SD cards with 32-bit-wide CMD23 capability.

If software is modified to skip TC occurrence and proceed with data comparison, it appears that all data was received correctly.

WORKAROUND

If the card is configured to send one more block (through the CMD23 argument) compared to what is configured in the host, then the Read transfer completes correctly (in this case, no DTO, TC occurs and data is correct).

REVISIONS IMPACTED

AM574x SR 1.0
AM576x SR 1.0

AM574x: 1.0

DRA75xP, DRA74xP, DRA77xP, DRA76xP: 1.0

TDA2Px: 1.0

AM576x: 1.0