MPC5676R DMA interrupts

[nicklabianco]

If I want to initiate DMA transfers using an external pin of the processor, which pins can I use? I found that there are 4 possible signals that can be used for this per reference manual pg. 3-15: IRQ[0], IRQ[1], IRQ[2], IRQ[3]. I found that these interrupts may be utilized on multiple uC pins as seen below. Am I able to use any of the pins below or only specific ones? How can I tell?

F25	ETPUC9_IRQ0_GPIO450	0
AF17	EMIOS14_IRQ0_GPIO193	0
F26	ETPUC10_IRQ1_GPIO451	1
AE16	EMIOS15_IRQ1_GPIO194	1
L4	BOOTCFG0_IRQ2_GPIO211	2
G22	ETPUC11_IRQ2_GPIO452	2
L3	BOOTCFG1_IRQ3_GPIO212	3
G23	ETPUC12_IRQ3_GPIO453	3
G24	ETPUC13_IRQ4_GPIO454	4
M3	PLLCFG0_IRQ4_GPIO208	4

[PetrS]

Hi,

Yes, you can use IRQ0-IRQ3 to start DMA transfers as you wrote.

You can select any pin by configuring alternate function of respective PCR register. For example to use IRQ0 on AF17 pad just configure

1. SIU.PCR[193].B.PA = 2; // select IRQ0 function
2. SIU.PCR[193.B.IBE = 1; // enable input buffer

Moreover you have to enable the edge detector in SIU_IREER or SIU_IFEER registers for an particular IRQ and enable DMA request in SIU_DIRSR.

The SIU_EIISR gives you a possibility to select the source for the external interrupt/DMA inputs. By default the IRQn sources are selected.

BR, Petr