dma_auto_restart_config_t Struct Reference

DMA auto-restart configuration. More...

#include <dma.h>

Data Fields
bool	enable_auto_restart
bool	infinite_restart
uint16_t	restart_count

Detailed Description

DMA auto-restart configuration.

Controls automatic restart behavior when a DMA command completes. Works in conjunction with register reload settings to enable continuous operation without CPU intervention.

Auto-restart sequence:

1. DMA command completes
2. Register reload occurs (if enabled via reg_reload_type)
3. Command automatically restarts (if auto-restart enabled):
   • If link_addr = 0: Restart the SAME command
   • If link_addr != 0: Jump to the LINKED command
4. Process repeats until count reached or manually stopped

Use cases:

• Continuous circular buffer operations
• Repeated transfers with same or reloaded parameters
• Periodic data movement without CPU intervention
• Multi-buffer ping-pong operations

Note: Auto-restart interacts with:

• Register reload settings (determines what gets restored)
• Command linking (link_addr determines restart target)
• CLEARCMD behavior (affects reloaded register values)

Auto-restart behavior:

• link_addr = 0: Restart same command (circular operation)
• link_addr != 0: Restart at linked command (chain operation)

Field Documentation

enable_auto_restart

bool dma_auto_restart_config_t::enable_auto_restart

Enable automatic restart after command completion

infinite_restart

bool dma_auto_restart_config_t::infinite_restart

true = restart infinitely, false = use restart_count

restart_count

uint16_t dma_auto_restart_config_t::restart_count

Number of restarts (when infinite_restart = false)