MAC7200 datasheet(560/976 Pages) FREESCALE

560 / 976 page

External Signal Description

MAC7200 Microcontroller Family Reference Manual, Rev. 2

482

Freescale Semiconductor

27.1.1

Features

The DMA Mux includes these distinctive features:

•

Programmable DMA Channel Mux allows assignment of any DMA source to any of the 16

available DMA channels.

•

Periodic triggering of up to 8 channels.

27.1.2

Modes of Operation

DMA Channels 0–7 may be used in the following modes, while Channels 8–15 may only be configured

to Disabled or Normal Mode.

•

Disabled Mode

In this mode, the DMA channel is disabled. Since disabling and enabling of DMA channels is done

primarily via the DMA registers, this mode is used mainly as the reset state for a DMA channel in

the DMA Channel Mux. It may also be used to temporarily suspend a DMA Channel while

reconfiguration of the system takes place (changing the period of a DMA trigger, for example).

•

Normal Mode

In this mode, a DMA source (such as SCI transmit or SCI receive for example) is routed directly

to the specified DMA channel. The operation of the DMA Mux in this mode is completely

transparent to the system.

•

Periodic Trigger Mode

In this mode, a DMA source may only request a DMA transfer (such as when a transmit buffer

becomes empty or a receive buffer becomes full) periodically. Configuration of the period is done

in the registers of the Periodic Interrupt Timer.

27.2

External Signal Description

The DMA Mux has no external pins.

SCI_A

SCI_B

ATD_A

eMIOS

8 channels on MAC72x2

16 channel on MAC72x1

(1 per channel)

PIM (GPIO)

(Use “always enabled” functionality)

TOTAL

Table 27-1. DMA Request Sources (Continued)

Peripheral

Number of DMA Channels

MAC7200 Datasheet(PDF) 560 Page - Freescale Semiconductor, Inc

MAC7200 Datasheet(HTML) 560 Page - Freescale Semiconductor, Inc

Html Pages

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 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL