Functional Description; Edma Basic Data Flow - NXP Semiconductors freescale KV4 Series Reference Manual

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DMA_TCDn_BITER_ELINKNO field descriptions (continued)

The channel-to-channel linking is disabled

The channel-to-channel linking is enabled

Starting Major Iteration Count

As the transfer control descriptor is first loaded by software, this 9-bit (ELINK = 1) or 15-bit (ELINK = 0)

field must be equal to the value in the CITER field. As the major iteration count is exhausted, the contents

of this field are reloaded into the CITER field.

NOTE: When the software loads the TCD, this field must be set equal to the corresponding CITER field;

otherwise, a configuration error is reported. As the major iteration count is exhausted, the

contents of this field is reloaded into the CITER field. If the channel is configured to execute a

single service request, the initial values of BITER and CITER should be 0x0001.

23.4 Functional description

The operation of the eDMA is described in the following subsections.

The basic flow of a data transfer can be partitioned into three segments.

As shown in the following diagram, the first segment involves the channel activation:

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KV4x Reference Manual, Rev. 2, 02/2015

Chapter 23 Direct Memory Access Controller (eDMA)