EP7212 Datasheet, PDF (89/136 Pages) Cirrus Logic – HIGH-PERFORMANCE, LOW-POWER SYSTEM-ON-CHIP WITH LCD CONTROLLER AND DIGITAL AUDIO INTERFACE(DAI)

EP7212
5.16.2 DAI Data Registers
The DAI contains three data registers: DAIDR0 addresses the top entry of the Right Channel Transmit
FIFO and bottom entry of the Right Channel Receive FIFO; DAIDR1 addresses the top and bottom entry
of the Left Channel Transmit and Receive FIFOs, respectively; and DAIDR2 is used to perform enable and
disable the DAI FIFOs.
5.16.2.1 DAIDR0 DAI Data Register 0
ADDRESS: 0x8000.2040
31:16
Reserved
31:16
Reserved
15:0
Bottom of Right Channel Receive FIFO
Read Access
15:0
Top of Right Channel Transmit FIFO
Write Access
When DAI Data Register 0 (DAIDR0) is read, the bottom entry of the Right Channel Receive FIFO is
accessed. As data is removed by the DAI’s receive logic from the incoming data frame, it is placed
into the top entry of the Right Channel Receive FIFO and is transferred down an entry at a time until
it reaches the last empty location within the FIFO. Data is removed by reading DAIDR0, which ac-
cesses the bottom entry of the right channel FIFO. After DAIDR0 is read, the bottom entry is invali-
dated, and all remaining values within the FIFO automatically transfer down one location.
When DAIDR0 is written, the top-most entry of the Right Channel Transmit FIFO is accessed. After a
write, data is automatically transferred down to the lowest location within the transmit FIFO which
does not already contain valid data. Data is removed from the bottom of the FIFO one value at a time
by the transmit logic, loaded into the correct position within the 64-bit transmit serial shifter, then se-
rially shifted out onto the SDOUT pin.
Table 51 shows DAIDR0. Note that the Transmit and Receive Right Channel FIFOs are cleared when
the device is reset, or by writing a zero to DAIEN (DAI disabled). Also, note that writes to reserved
bits are ignored and reads return zeros.
Bit
0:15
16:31
Description
RIGHT CHANNEL DATA: Transmit / Receive Right Channel FIFO Data
Read — Bottom of Right Channel Receive FIFO data
Write — Top of Right Channel Transmit FIFO data
Reserved
Table 51. DAI Data Register 0
DS474PP1
89