Operation Flow Chart - Samsung S3C2416 User Manual

AC97 CONTROLLER S3C2416X RISC MICROPROCESSOR

3 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 the AC97 audio-codec. This assumes that GPIO is already ready. Then you make
codec ready interrupt enable. You can check codec ready interrupt by polling or interrupt. When interrupt is
occurred, you must de-assert codec ready interrupt. Now then you can 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) is not empty, then let data be transmitted. In addition, you can previously turn on AC-Link.
System reset or Cold reset
Set GPIO and Release
INTMSK/SUBINTMSK bits
Enable Codec Ready interrupt
No
No
Time out condition ?
Codec Ready interrupt ?
Yes
Disable Codec Ready interrupt
Controller off
DMA operation or
PIO (Interrupt or Polling) operation
Figure 24-3. AC97 Operation Flow Chart
24-4