NS9750 Training Hardware

1
NS9750 - Training Hardware
2
BBUS DMA Controller
3
BBUS DMA

• 16 channels per DMA controller
• Provides DMA support for the serial controllers
  and the IEEE-1284 interface
• Provides DMA support for the USB Device
  controller
• Supports single and burst transfers
• Supports end-of-packet signaling to close an open
  buffer
• Supports fly-by-read transfers to move data from
  system memory to a peripheral
• Supports fly-by-write transfers to move data from
  a peripheral to system memory
• Per channel interrupts to facilitate processor
  communications
• Status feedback communicates error conditions

4
BBUS DMA

• Create at least two buffer descriptors in system
  memory.
• Initialize the buffer descriptor pointer
• Specify the transfer mode
• Enable the desired interrupts
• Enable the DMA channel
• Service interrupts when they occur