Microchip Technology MA320001 Data Sheet
© 2011 Microchip Technology Inc.
DS61143H-page 97
PIC32MX3XX/4XX
10.0
DIRECT MEMORY ACCESS
(DMA) CONTROLLER
(DMA) CONTROLLER
The PIC32MX Direct Memory Access (DMA) controller
is a bus master module useful for data transfers
between different devices without CPU intervention.
The source and destination of a DMA transfer can be
any of the memory mapped modules existent in the
PIC32MX (such as Peripheral Bus (PBUS) devices:
SPI, UART, PMP, and so on) or memory itself.
is a bus master module useful for data transfers
between different devices without CPU intervention.
The source and destination of a DMA transfer can be
any of the memory mapped modules existent in the
PIC32MX (such as Peripheral Bus (PBUS) devices:
SPI, UART, PMP, and so on) or memory itself.
Following are some of the key features of the DMA
controller module:
controller module:
• Four Identical Channels, each featuring:
- Auto-Increment Source and Destination
Address Registers
- Source and Destination Pointers
- Memory to Memory and Memory to
- Memory to Memory and Memory to
Peripheral Transfers
• Automatic Word-Size Detection:
- Transfer Granularity, down to byte level
- Bytes need not be word-aligned at source
- Bytes need not be word-aligned at source
and destination
• Fixed Priority Channel Arbitration
• Flexible DMA Channel Operating Modes:
• Flexible DMA Channel Operating Modes:
- Manual (software) or automatic (interrupt)
DMA requests
- One-Shot or Auto-Repeat Block Transfer
modes
- Channel-to-channel chaining
• Flexible DMA Requests:
- A DMA request can be selected from any of
the peripheral interrupt sources
- Each channel can select any (appropriate)
observable interrupt as its DMA request
source
source
- A DMA transfer abort can be selected from
any of the peripheral interrupt sources
- Pattern (data) match transfer termination
• Multiple DMA Channel Status Interrupts:
- DMA channel block transfer complete
- Source empty or half empty
- Destination full or half-full
- Source empty or half empty
- Destination full or half-full
- DMA transfer aborted due to an external
event
- Invalid DMA address generated
• DMA Debug Support Features:
- Most recent address accessed by a DMA
channel
- Most recent DMA channel to transfer data
• CRC Generation Module:
- CRC module can be assigned to any of the
available channels
- CRC module is highly configurable
FIGURE 10-1:
DMA BLOCK DIAGRAM
Note 1: This data sheet summarizes the features
of the PIC32MX3XX/4XX family of
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to Section 31. “Direct
Memory Access (DMA) Controller”
(DS61117) of the “PIC32 Family
Reference Manual”, which is available
from the Microchip web site
(
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to Section 31. “Direct
Memory Access (DMA) Controller”
(DS61117) of the “PIC32 Family
Reference Manual”, which is available
from the Microchip web site
(
www.microchip.com/PIC32
).
2: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
available on all devices. Refer to
in
this data sheet for device-specific register
and bit information.
and bit information.
Address
Channel 0
Channel 1
Channel n
Global Control
(DMACON)
Bus
Channel Priority
Arbitration
SE
L
SE
L
Y
I
0
I
1
I
2
I
n
System IRQ
INT Controller
Device Bus + Bus Arbitration
Decoder
Peripheral Bus
Control
Control
Control
Interface