Allwinner A20 - Page 707

A20 User Manual (Revision 1.2) Copyright © 2013 Allwinner Technology Co., Ltd. All Rights Reserved. Page 707 / 812
Offset: 0x14
Register Name: DA_FCTL
Default Value: 0x0004_00F0
Bit
Read/Write
Default
Description
01: Expanding received sample sign bit at MSB of
DA_RXFIFO register.
10: Truncating received samples at high half-word of
DA_RXFIFO register and low half-word of DA_RXFIFO
register is filled by ‘0’.
11: Truncating received samples at low half-word of
DA_RXFIFO register and high half-word of DA_RXFIFO
register is expanded by its sign bit.
Example for 20-bits received audio sample:
Mode 0: RXFIFO[31:0] = {FIFO_O[19:0], 12’h0}
Mode 1: RXFIFO[31:0] = {12{FIFO_O[19]}, FIFO_O[19:0]}
Mode 2: RXFIFO[31:0] = {FIFO_O[19:4], 16’h0}
Mode 3: RXFIFO[31:0] = {16{FIFO_O[19], FIFO_O[19:4]}
6.9.5.7. DIGITAL AUDIO FIFO STATUS REGISTER
Offset: 0x18
Register Name: DA_FSTA
Default Value: 0x1080_0000
Bit
Read/Write
Default
Description
31:29
/
/
/
28
R
1
TXE
TX FIFO Empty
0: No room for new sample in TX FIFO
1: More than one room for new sample in TX FIFO (>= 1 word)
27:24
/
/
/
23:16
R
0x80
TXE_CNT
TX FIFO Empty Space Word Counter
15:9
/
/
/
8
R
0
RXA
RX FIFO Available
0: No available data in RX FIFO
1: More than one sample in RX FIFO (>= 1 word)
7
/
/
/