MCBSTM32EXL Keil, MCBSTM32EXL Datasheet - Page 469

• Manufacturer Part Number: MCBSTM32EXL
• Description: BOARD EVALUATION FOR STM32F103ZE
• Manufacturer: Keil

Specifications of MCBSTM32EXL

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

RM0008
Depending on the TXACT and RXACT flags, the FIFO can be disabled, transmit enabled, or
receive enabled. TXACT and RXACT are driven by the data path subunit and are mutually
exclusive:
●
Table 126. Transmit FIFO status flags
●
TXFIFOF
TXFIFOE
TXFIFOHE
TXDAVL
TXUNDERR
–
–
Transmit FIFO:
Data can be written to the transmit FIFO through the AHB interface when the SDIO is
enabled for transmission.
The transmit FIFO is accessible via 32 sequential addresses. The transmit FIFO
contains a data output register that holds the data word pointed to by the read pointer.
When the data path subunit has loaded its shift register, it increments the read pointer
and drives new data out.
If the transmit FIFO is disabled, all status flags are deasserted. The data path subunit
asserts TXACT when it transmits data.
Receive FIFO
When the data path subunit receives a word of data, it drives the data on the write
databus. The write pointer is incremented after the write operation completes. On the
read side, the contents of the FIFO word pointed to by the current value of the read
pointer is driven onto the read databus. If the receive FIFO is disabled, all status flags
are deasserted, and the read and write pointers are reset. The data path subunit
asserts RXACT when it receives data.
The receive FIFO is accessible via 32 sequential addresses.
Flag
The transmit FIFO refers to the transmit logic and data buffer when TXACT is
asserted
The receive FIFO refers to the receive logic and data buffer when RXACT is
asserted
Set to high when all 32 transmit FIFO words contain valid data.
Set to high when the transmit FIFO does not contain valid data.
Set to high when 8 or more transmit FIFO words are empty. This flag can be used
as a DMA request.
Set to high when the transmit FIFO contains valid data. This flag is the inverse of
the TXFIFOE flag.
Set to high when an underrun error occurs. This flag is cleared by writing to the
SDIO Clear register.
Doc ID 13902 Rev 9
Table 127
Secure digital input/output interface (SDIO)
Description
lists the receive FIFO status flags.
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