Channel Assignments; Μdma Channel Assignment Mapping - Texas Instruments Concerto F28M35 Series Technical Reference Manual

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16.3.1 Channel Assignments

µDMA channels 0-31 are assigned to different peripherals according to the following table. The DMA
Channel Map (DMACHMAPx) registers can be used to specify the first, second, or third channel mapping
assignment.primary or secondary assignment.
NOTE: Channels noted in the table as "Available for software" may be assigned to peripherals in the
future. However, they are currently available for software use. Channel 30 is dedicated for
software use.
The USB endpoints mapped to µDMA channels 0-3 can be changed with the USBDMASEL
register.
Because of the way the μDMA controller interacts with peripherals, the μDMA channel for the
peripheral must be enabled in order for the μDMA controller to be able to read and write the
peripheral registers, even if a different μDMA channel is used to perform the μDMA transfer.
To minimize confusion and chance of software errors, it is best practice to use a peripheral's
μDMA channel for performing all μDMA transfers for that peripheral, even if it is processor-
triggered and using AUTO mode, which could be considered a software transfer. Note that if
the software channel is used, interrupts occur on the dedicated μDMA interrupt vector. If the
peripheral channel is used, then the interrupt occurs on the interrupt vector for the peripheral.
DMACHALT Encoding
DMACHMAPx Encoding
µDMA Channel
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
SPRUH22I – April 2012 – Revised November 2019
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Table 16-1. µDMA Channel Assignment Mapping
0
0
First Assignment Second Assignment
USB Endpoint 1 Receive UART2 Receive
USB Endpoint 1 Transmit UART2 Transmit
USB Endpoint 2 Receive General-Purpose Timer 3A
USB Endpoint 2 Transmit General-Purpose Timer 3B
USB Endpoint 3 Receive General-Purpose Timer 2A
USB Endpoint 3 Transmit General-Purpose Timer 2B
Ethernet Receive General-Purpose Timer 2A
Ethernet Transmit General-Purpose Timer 2B
UART0 Receive UART1 Receive
UART0 Transmit UART1 Transmit
SSI0 Receive SSI1 Receive
SSI0 Transmit SSI1 Transmit
Available for software UART2 Receive
Available for software UART2 Transmit
Reserved General-Purpose Timer 2A
Reserved General-Purpose Timer 2B
Reserved Available for software
Reserved Available for software
General-Purpose Timer 0A General-Purpose Timer 1A
General-Purpose Timer 0B General-Purpose Timer 1B
Adv GPIO / EPI0RX (EPI
General-Purpose Timer 1A
Non-blocking read FIFO)
Adv GPIO / EPI0TX (EPI
General-Purpose Timer 1B
Write FIFO)
UART1 Receive Available for software
UART1 Transmit Available for software
SSI1 Receive Reserved
SSI1 Transmit Reserved
Copyright © 2012–2019, Texas Instruments Incorporated
1
1
Third Assignment
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
SSI2 Receive
SSI2 Transmit
SSI3 Receive
SSI3 Transmit
UART3 Receive
UART3 Transmit
UART4 Receive
UART4 Transmit
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
M3 Micro Direct Memory Access ( µDMA)
Functional Description
2
1151