Datasheet

 2012-2013 Microchip Technology Inc. DS60001185C-page 131
PIC32MX330/350/370/430/450/470
10.0 DIRECT MEMORY ACCESS
(DMA) CONTROLLER
The PIC32 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 PIC32 (such
as Peripheral Bus (PBUS) devices: SPI, UART, PMP,
etc.) or memory itself.
Following are some of the key features of the DMA
controller module:
• Four identical channels, each featuring:
- Auto-increment source and destination
address registers
- Source and destination pointers
- 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
and destination
• Fixed priority channel arbitration
• 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
- 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
- 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 PIC32MX330/350/370/430/450/
470 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”
(DS60001117) in 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
Section 4.0 “Memory Organization” in
this data sheet for device-specific register
and bit information.
Address Decoder
Channel 0 Control
Channel 1 Control
Channel n Control
Global Control
(DMACON)
Bus Interface
Channel Priority
Arbitration
S
E
L
S
E
L
Y
I
0
I
1
I
2
I
n
System IRQINT Controller
Device Bus + Bus Arbitration
Peripheral Bus