Features - STMicroelectronics SPC572L series Reference Manual

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20.1.2

Features

The DMAMUX module provides these features:
•
Up to 64 peripheral slots and up to six always-on slots can be routed to 16 channels.
•
16 independently selectable DMA channel routers.
–
•
Each channel router can be assigned to one of the possible peripheral DMA slots or to
one of the always-on slots.
20.1.3 Modes of operation
The following operating modes are available:
•
Disabled mode
In this mode, the DMA channel is disabled. Because disabling and enabling of DMA
channels is done primarily via the DMA configuration 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, for example, changing the period of a DMA trigger.
•
Normal mode
In this mode, a DMA source is routed directly to the specified DMA channel. The
operation of the DMAMUX 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 (PIT). This mode is
available only for channels 0–5.
20.2 External signal description
The DMAMUX has no external pins.
20.3 Memory map/register definition
This section provides a detailed description of all memory-mapped registers in the
DMAMUX.
Absolute
address
(hex)
0 Channel Configuration register (DMAMUX_CHCFG0)
1 Channel Configuration register (DMAMUX_CHCFG1)
2 Channel Configuration register (DMAMUX_CHCFG2)
3 Channel Configuration register (DMAMUX_CHCFG3)
4 Channel Configuration register (DMAMUX_CHCFG4)
The first eight channels additionally provide a trigger functionality.
Table 206. DMAMUX memory map
Register name
DocID027809 Rev 4
Direct Memory Access Multiplexer (DMAMUX)
Width
Access
(in bits)
8
8
8
8
8
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