Samsung S3C6400X User Manual page 1064

AC97 CONTROLLER
OPERATION FLOW CHART
When you initialize the AC97 controller, you must assert system reset or cold reset, because we don't know the
previous state of the external AC97 audio-codec. This assures that GPIO is already ready. Then you enable the
codec ready interrupt. You can check codec ready interrupt by polling or interrupt. When interrupt is occurred, you
must de-assert codec ready interrupt. You can now transmit data from memory to register or from register to
memory by using DMA or PIO (directly to write data to register). If internal FIFOs (TX FIFO or RX FIFO) are not
empty, then let data be transmitted. In addition, you can previously turn on AC-Link.
Time out condition ?
Controller off
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
35-4
Specifications and information herein are subject to change without notice.
No
No
Yes
Figure 35-3. AC97 Operation Flow Chart
S3C6400 RISC MICROPROCESSOR
System reset or Cold reset
Set GPIO and Release
INTMSK/SUBINTMSK bits
Enable Codec Ready interrupt
Codec Ready interrupt ?
Disable Codec Ready interrupt
DMA operation or
PIO (Interrupt or Polling) operation