ST STM32G431 User Manual

RM0440 Rev 4 1801/2126
RM0440 Serial audio interface (SAI)
1858
Figure 612. Slot size configuration with FBOFF = 0 in SAI_xSLOTR
It is possible to choose the position of the first data bit to transfer within the slots. This offset
is configured by FBOFF[4:0] bits in the SAI_xSLOTR register. 0 values will be injected in
transmitter mode from the beginning of the slot until this offset position is reached. In
reception, the bit in the offset phase is ignored. This feature targets the LSB justified
protocol (if the offset is equal to the slot size minus the data size).
Figure 613. First bit offset
It is mandatory to respect the following conditions to avoid bad SAI behavior:
FBOFF ≤(SLOTSZ - DS),
DS ≤SLOTSZ,
NBSLOT x SLOTSZ ≤FRL (frame length),
The number of slots must be even when bit FSDEF in the SAI_xFRCR register is set.
In AC’97 and SPDIF protocol (bit PRTCFG[1:0] = 10 or PRTCFG[1:0] = 01), the slot size is
automatically set as defined in Section 40.3.11: AC’97 link controller.
MS30033V1
00..00
00..00
X..X
XX.. XX
X: don’t care
Audio block is transmitter
Slot size = data size
data size
data size
data size
data size
slotx
slotx
slotx
16-bit
32-bit
Audio block is receiver
Slot size = data size
data size
data size
data size
slotx
slotx
slotx
16-bit
32-bit
data size
MS30034V1
XX .. XX
00
00..00
X: don’t care
Audio block is transmitter
Slot size = data size
data size
data size
data size
data size
slotx
slotx
slotx
16-bit
32-bit
Audio block is receiver
00
FBOFF
FBOFF = SLOT SZ -DS
XX
Slot size = data size
data size
data size
data size
data size
slotx
slotx
slotx
16-bit
32-bit
XX
FBOFF
FBOFF = SLOT SZ -DS

ST STM32G431 Specifications

General

Brand	ST
Model	STM32G431
Category	Microcontrollers
Language	English