Serial peripheral interface / integrated interchip sound (SPI/I2S) RM0440
1784/2126 RM0440 Rev 4
39.9.3 SPI status register (SPIx_SR)
Address offset: 0x08
Reset value: 0x0002
Bit 2 SSOE: SS output enable
0: SS output is disabled in master mode and the SPI interface can work in multimaster
configuration
1: SS output is enabled in master mode and when the SPI interface is enabled. The SPI
interface cannot work in a multimaster environment.
Note: This bit is not used in I
2
S mode and SPI TI mode.
Bit 1 TXDMAEN: Tx buffer DMA enable
When this bit is set, a DMA request is generated whenever the TXE flag is set.
0: Tx buffer DMA disabled
1: Tx buffer DMA enabled
Bit 0 RXDMAEN: Rx buffer DMA enable
When this bit is set, a DMA request is generated whenever the RXNE flag is set.
0: Rx buffer DMA disabled
1: Rx buffer DMA enabled
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Res. Res. Res. FTLVL[1:0] FRLVL[1:0] FRE BSY OVR MODF
CRCE
RR
UDR CHSIDE TXE RXNE
rrrrrrrrrc_w0r r rr
Bits 15:13 Reserved, must be kept at reset value.
Bits 12:11 FTLVL[1:0]: FIFO transmission level
These bits are set and cleared by hardware.
00: FIFO empty
01: 1/4 FIFO
10: 1/2 FIFO
11: FIFO full (considered as FULL when the FIFO threshold is greater than 1/2)
Note: This bit is not used in I
2
S mode.
Bits 10:9 FRLVL[1:0]: FIFO reception level
These bits are set and cleared by hardware.
00: FIFO empty
01: 1/4 FIFO
10: 1/2 FIFO
11: FIFO full
Note: These bits are not used in I²S mode and in SPI receive-only mode while CRC
calculation is enabled.
Bit 8 FRE: Frame format error
This flag is used for SPI in TI slave mode and I
2
S slave mode. Refer to Section 39.5.11: SPI
error flags and Section 39.7.8: I2S error flags.
This flag is set by hardware and reset when SPIx_SR is read by software.
0: No frame format error
1: A frame format error occurred
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