PXD20RM Datasheet, PDF (1028/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

required that allows the LINFlexD FSMs to be reset in case this timeout state is reached or in any other
case. Timeout counter can be re-written by software at any time to extend timeout period.
Table 27-50. TCD settings (UART node, RX mode)
TCD Field
CITER[14:0]
BITER[14:0]
NBYTES[31:0]
SADDR[31:0]
SOFF[15:0]
SSIZE[2:0]
SLAST[31:0]
DADDR[31:0]
DOFF[15:0]
DSIZE[2:0]
DLAST_SGA[31:0]
INT_MAJ
D_REQ
START
Value
8 bits data 16 bits data
Description
M
M
1
2
BDRM address
0
0
0
RAM address
1
0
-M
0/1
1
0
1
2
1
-M * 2
Multiple iterations for the “major” loop
Multiple iterations for the “major” loop
Minor loop transfer = 1 or 2 bytes
SADDR = BDRM + 0x3 for byte transfer
SADDR = BDRM + 0x2 for half-word
transfer
No increment (FIFO)
Byte/Half-word transfer
Byte/Half-word increment
Byte/Half-word transfer
No scatter/gather processing
Interrupt disabled/enabled
Only on the last TCD of the chain.
No software request
27.11.7 Use cases and limitations
• In LIN slave mode, the DMA capability can be used only if the ID filtering mode is activated. The
number of ID filters enabled must be equal to the number of DMA channels enabled. The
correspondence between channel # and ID filter is based on IFMI (identifier filter match index).
• In LIN master mode both the DMA channels (TX and RX) must be enabled in case the DMA
capability is required.
• In UART mode the DMA capability can be used only if the UART Tx/Rx buffers are configured
as FIFOs.
• DMA and CPU operating modes are mutually exclusive for the data/frame transfer on a UART or
LIN node. Once a DMA transfer is finished the CPU can handle subsequent accesses.
• Error management must be always executed via CPU enabling the related error interrupt sources.
The DMA capability does not provide support for the error management. Error management means
checking status bits, handling IRQs and potentially canceling DMA transfers.
• The DMA programming model must be coherent with the TCD setting defined in this document.
27-72
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor