DS785UM1
22-7
Copyright 2007 Cirrus Logic
AC’97 Controller
EP93xx User’s Guide
2
2
2
2
22
Address:
AC97DR1 - 0x8088_0000 - Read/Write
AC97DR2 - 0x8088_0020 - Read/Write
AC97DR3 - 0x8088_0040 - Read/Write
AC97DR4 - 0x8088_0060 - Read/Write
Definition:
The AC97DR registers are read / write data registers that are normally 20 bits
wide. In 16-bit compact mode, all 32 available bits are used. This register is
zero at reset.
Bit Descriptions:
RSVD:
Reserved. Unknown During Read.
DATA:
Write - Transmit FIFO: The AC97TXCR register qualifies
the data within the TX FIFO.
Read - Receive FIFO: The AC97RXCR register qualifies
the data within the FIFO.
For words to be transmitted:
•
If the FIFOs are enabled, data written to this location is pushed onto the transmit FIFO.
•
If the FIFOs are not enabled, data is stored in the transmitter holding register (the bottom
word of the transmit FIFO).
For received words:
•
If the FIFOs are enabled, the data received is pushed onto the receive FIFO.
•
If the FIFOs are not enabled, the data received is stored in the receiving holding register
(the bottom word of the receive FIFO).
The receive FIFO is 21 bits wide. The 21
st
bit, the receive overrun error status, can only be
read via the AC97ISR registers. The receive overrun error status bit is transferred down to
the FIFO buffer along with the overrun data value.
AC97RXCRx
Address:
AC97RXCR1 - 0x8088_0004 - Read/Write
AC97RXCR2 - 0x8088_0024 - Read/Write
AC97RXCR3 - 0x8088_0044 - Read/Write
AC97RXCR4 - 0x8088_0064 - Read/Write
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
RSVD
TOC
FDIS
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
CM
RSIZE
RX12
RX11
RX10
RX9
RX8
RX7
RX6
RX5
RX4
RX3
RX2
RX1
REN
Summary of Contents for EP93 Series
Page 28: ...P 6 DS785UM1 Copyright 2007 Cirrus Logic Preface EP93xx User s Guide PP P ...
Page 162: ...5 36 DS785UM1 Copyright 2007 Cirrus Logic System Controller EP93xx User s Guide 55 5 ...
Page 576: ...15 18 DS785UM1 Copyright 2007 Cirrus Logic UART2 EP93xx User s Guide 1515 15 ...
Page 634: ...17 38 DS785UM1 Copyright 2007 Cirrus Logic IrDA EP93xx User s Guide 1717 17 ...
Page 648: ...19 6 DS785UM1 Copyright 2007 Cirrus Logic Watchdog Timer EP93xx User s Guide 1919 19 ...
Page 688: ...21 32 DS785UM1 Copyright 2007 Cirrus Logic I2S Controller EP93xx User s Guide 2121 21 ...
Page 790: ...27 20 DS785UM1 Copyright 2007 Cirrus Logic IDE Interface EP93xx User s Guide 2727 27 ...
Page 808: ...28 18 DS785UM1 Copyright 2007 Cirrus Logic GPIO Interface EP93xx User s Guide 2828 28 ...