Table of Contents
Advertisement
System Software
Enable ENLINK
Check AC'97 status
Start up AC-link
Register setting such as gain (*)
Clear DMA buffer
Configure DMAC
Start DMA Channel and
enable receive-data DMA
Read from DMA buffer and update
DMA descriptor (repeatedly)
Stop updating DMA descriptor
Check completion status
Disable receive-data DMA
Dummy read from data register to
clear pending DMA request if any
Disable ENLINK
(*) Register settings such as gain can be made during data recording
ACLC and DMAC
Deassert ACRESET*
CODECRDY Interrupt
Start receiving data from slot
Start receive-data DMA
DMAC generates Transfer
Completion interrupt (repeatedly)
DMAC channel goes inactive
DMA overrun error occurs
Receive-data DMA halts
Assert ACRESET *
Figure 14.3.4 Audio Recording Process Flow
14-6
Chapter 14 AC-link Controller
Start BITCLK
Set CODEC Ready
Start recording audio
ADC Ready response
Set gain, etc.
Send sample data
Stop AC-link
Stop BITCLK
AC'97
Advertisement
Table of Contents
