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DocID018909 Rev 11 1041/1731

RM0090 Secure digital input/output interface (SDIO)

1067

ERASE_TIMEOUT

This 6-bit field indicates TERASE and the value indicates the erase timeout from offset

when multiple AUs are being erased as specified by ERASE_SIZE. The range of

ERASE_TIMEOUT can be defined as up to 63 seconds and the card manufacturer can

choose any combination of ERASE_SIZE and ERASE_TIMEOUT depending on the

implementation. Determining ERASE_TIMEOUT determines the ERASE_SIZE.

ERASE_OFFSET

This 2-bit field indicates TOFFSET and one of four values can be selected. This field is

meaningless if the ERASE_SIZE and ERASE_TIMEOUT fields are set to 0.

31.4.13 SD I/O mode

SD I/O interrupts

To allow the SD I/O card to interrupt the MultiMediaCard/SD module, an interrupt function is

available on a pin on the SD interface. Pin 8, used as SDIO_D1 when operating in the 4-bit

SD mode, signals the cards interrupt to the MultiMediaCard/SD module. The use of the

interrupt is optional for each card or function within a card. The SD I/O interrupt is level-

sensitive, which means that the interrupt line must be held active (low) until it is either

recognized and acted upon by the MultiMediaCard/SD module or deasserted due to the end

of the interrupt period. After the MultiMediaCard/SD module has serviced the interrupt, the

interrupt status bit is cleared via an I/O write to the appropriate bit in the SD I/O card’s

internal registers. The interrupt output of all SD I/O cards is active low and the application

must provide external pull-up resistors on all data lines (SDIO_D[3:0]). The

MultiMediaCard/SD module samples the level of pin 8 (SDIO_D/IRQ) into the interrupt

detector only during the interrupt period. At all other times, the MultiMediaCard/SD module

ignores this value.

Table 164. Erase timeout field

ERASE_TIMEOUT Value definition

00 Erase timeout calculation is not supported.

01 1 [sec]

02 2 [sec]

03 3 [sec]

--------- ---------

63 63 [sec]

Table 165. Erase offset field

ERASE_OFFSET Value definition

0h 0 [sec]

1h 1 [sec]

2h 2 [sec]

3h 3 [sec]

STMicroelectronics STM32F407 User Manual

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