50.12.19 SDMMC Normal Interrupt Status Register (SD_SDIO)

Note: This register configuration is specific to the SD/SDIO operation mode.
Name: SDMMC_NISTR (SD_SDIO)
Offset: 0x30
Reset: 0x0000
Property: Read/Write

Bit 15141312111098 
 ERRINT      CINT 
Access RR/W 
Reset 00 
Bit 76543210 
 CREMCINSBRDRDYBWRRDYDMAINTBLKGETRFCCMDC 
Access R/WR/WR/WR/WR/WR/WR/WR/W 
Reset 00000000 

Bit 15 – ERRINT Error Interrupt

If any of the bits in SDMMC_EISTR are set, then this bit is set. Therefore, the user can efficiently test for an error by checking this bit first. This bit is read-only.

ValueDescription
0

No error.

1

Error.

Bit 8 – CINT Card Interrupt

Writing this bit to '1' does not clear this bit. It is cleared by resetting the SD card interrupt factor. In 1-bit mode, the SDMMC detects the Card Interrupt without SDCLK to support wakeup. In 4-bit mode, the Card Interrupt signal is sampled during the interrupt cycle, so there are some sample delays between the interrupt signal from the SD card and the interrupt to the system.

When this bit is set to '1' and the user needs to start this interrupt service, Card Interrupt Status Enable (CINT) in SDMMC_NISTER may be set to '0' in order to clear the card interrupt statuses latched in the SDMMC and to stop driving the interrupt signal to the system. After completion of the card interrupt service (it should reset interrupt factors in the SD card and the interrupt signal may not be asserted), set SDMMC_NISTER.CINT to '1' and start sampling the interrupt signal again.

Interrupt detected by DAT[1] is supported when there is one card per slot.

This bit can only be set to 1 if SDMMC_NISTER.CINT is set to 1. An interrupt can only be generated if SDMMC_NISIER.CINT is set to 1.

ValueDescription
0

No card interrupt.

1

Card interrupt.

Bit 7 – CREM Card Removal

This status is set to '1' if Card Inserted (CARDINS) in SDMMC_PSR changes from '1' to '0'. When the user writes this bit to '1' to clear this status, the status of SDMMC_PSR.CARDINS must be confirmed because the card detect state may possibly be changed when the user clears this bit and no interrupt event can be generated.

This bit can only be set to '1' if SDMMC_NISTER.CREM is set to '1'. An interrupt can only be generated if SDMMC_NISIER.CREM is set to '1'.

Writing this bit to '1' clears the bit.

ValueDescription
0

Card state unstable or card inserted.

1

Card removed.

Bit 6 – CINS Card Insertion

This status is set if Card Inserted (CARDINS) in SDMMC_PSR changes from '0' to '1'. When the user writes this bit to '1' to clear this status, the status of SDMMC_PSR.CARDINS must be confirmed because the card detect state may possibly be changed when the user clears this bit and no interrupt event can be generated.

This bit can only be set to '1' if SDMMC_NISTER.CINS is set to '1'. An interrupt can only be generated if SDMMC_NISIER.CINS is set to '1'.

Writing this bit to '1' clears the bit.

ValueDescription
0

Card state unstable or card removed.

1

Card inserted.

Bit 5 – BRDRDY Buffer Read Ready

This status is set to '1' if the Buffer Read Enable (BUFRDEN) changes from '0' to '1'. See BUFRDEN in SDMMC_PSR. While processing the tuning procedure (Execute Tuning (EXTUN) in SDMMC_HC2R is set to '1'), BRDRDY is set to '1' for every CMD19 execution.

This bit can only be set to '1' if SDMMC_NISTER.BRDRDY is set to '1'. An interrupt can only be generated if SDMMC_NISIER.BRDRDY is set to '1'.

Writing this bit to '1' clears the bit.

ValueDescription
0

Not ready to read buffer.

1

Ready to read buffer.

Bit 4 – BWRRDY Buffer Write Ready

This status is set to '1' if the Buffer Write Enable (BUFWREN) changes from '0' to '1'. See BUFWREN in SDMMC_PSR.

This bit can only be set to '1' if SDMMC_NISTER.BWRRDY is set to '1'. An interrupt can only be generated if SDMMC_NISIER.BWRRDY is set to '1'.

Writing this bit to '1' clears the bit.

ValueDescription
0

Not ready to write buffer.

1

Ready to write buffer.

Bit 3 – DMAINT DMA Interrupt

This status is set if the SDMMC detects the Host SDMA Buffer boundary during transfer. See SDMA Buffer Boundary (BOUNDARY) in SDMMC_BSR.

In case of ADMA, by setting the “int” field in the descriptor table, the SDMMC raises this status flag when the descriptor line is completed. This status flag does not rise after Transfer Complete (TRFC).

This bit can only be set to '1' if SDMMC_NISTER.DMAINT is set to '1'. An interrupt can only be generated if SDMMC_NISIER.DMAINT is set to '1'.

Writing this bit to '1' clears the bit.

ValueDescription
0

No DMA Interrupt.

1

DMA Interrupt.

Bit 2 – BLKGE Block Gap Event

If the Stop At Block Gap Request (STPBGR) in SDMMC_BGCR is set to 1, this bit is set when either a read or a write transaction is stopped at a block gap. If STPBGR is not set to 1, this bit is not set to 1.

In the case of a Read transaction:

This bit is set at the falling edge of the DAT Line Active (DLACT) status (when the transaction is stopped at SD bus timing). The Read Wait must be supported in order to use this function. See section “Read Transaction Wait / Continue Timing” in the “SD Host Controller Simplified Specification V3.00” about the detailed timing.

In the case of a Write transaction:

This bit is set at the falling edge of the Write Transfer Active (WTACT) status (after getting the CRC status at SD bus timing). See section “Write Transaction Wait / Continue Timing” in the “SD Host Controller Simplified Specification V3.00” for more details on the sequence of events.

This bit can only be set to '1' if SDMMC_NISTER.BLKGE is set to '1'. An interrupt can only be generated if SDMMC_NISIER.BLKGE is set to '1'.

Writing this bit to '1' clears the bit.

ValueDescription
0

No block gap event.

1

Transaction stopped at block gap.

Bit 1 – TRFC Transfer Complete

This bit is set when a read/write transfer and a command with Busy is completed.

In the case of a Read Transaction:

This bit is set at the falling edge of the Read Transfer Active Status. The interrupt is generated in two cases. The first is when a data transfer is completed as specified by the data length (after the last data was read to the system). The second is when data has stopped at the block gap and completed the data transfer by setting the Stop At Block Gap Request (STPBGR) in SDMMC_BGCR (after valid data was read to the system). See section “Read Transaction Wait / Continue Timing” in the “SD Host Controller Simplified Specification V3.00” for more details on the sequence of events.

In the case of a Write Transaction:

This bit is set at the falling edge of the DAT Line Active (DLACT) status. This interrupt is generated in two cases. The first is when the last data is written to the card as specified by the data length and the Busy signal is released. The second is when data transfers are stopped at the block gap by setting Stop At Block Gap Request (STPBGR) in SDMMC_BGCR and data transfers are completed. (After valid data is written to the card and the Busy signal is released). See section “Write Transaction Wait / Continue Timing” in the “SD Host Controller Simplified Specification V3.00” for more details on the sequence of events.

In the case of command with Busy:

This bit is set when Busy is deasserted. See DAT Line Active (DLACT) and Command Inhibit (DAT) (CMDINHD) in SDMMC_PSR.

This bit can only be set to '1' if SDMMC_NISTER.TRFC is set to '1'. An interrupt can only be generated if SDMMC_NISIER.TRFC is set to '1'.

Writing this bit to '1' clears the bit.

The table below shows that Transfer Complete (TRFC) has a higher priority than Data Timeout Error (DATTEO). If both bits are set to '1', execution of a command can be considered to be completed.

TRFC DATTEO Status Meaning
0 0 Interrupted by another factor
0 1 Timeout occurred during transfer
1 Don’t Care Command execution complete
ValueDescription
0

Command execution is not complete.

1

Command execution is complete.

Bit 0 – CMDC Command Complete

This bit is set when getting the end bit of the command response. Auto CMD12 and Auto CMD23 consist of two responses. Command Complete is not generated by the response of CMD12 or CMD23, but it is generated by the response of a read/write command. See Command Inhibit (CMD) in SDMMC_PSR for details on how to control this bit.

This bit can only be set to 1 if SDMMC_NISTER.CMDC is set to 1. An interrupt can only be generated if SDMMC_NISIER.CMDC is set to 1.

Writing this bit to 1 clears the bit.

The table below shows that Command Timeout Error (CMDTEO) has a higher priority than Command Complete (CMDC). If both bits are set to 1, it can be considered that the response was not received correctly.

CMDC CMDTEO Status Meaning
0 0 Interrupted by another factor
Don’t care 1 Response not received within 64 SDCLK cycles
1 0 Response received
ValueDescription
0

No command complete.

1

Command complete.