Figure 832. Master Node — Dma Tx Fsm (Concept Scheme) - STMicroelectronics SPC572L series Reference Manual

RM0400
Set Token_DMA_Rx to enable the DMA
Rx interface
50.3.5.4 Master node — RX mode
On a master node in RX mode, the DMA interface requires a single RX channel. Each TCD
controls a single frame, except for the extended frames (multiple TCDs). The memory map
associated with the TCD chain (RAM area and LINFlexD registers) is given in
Figure 832. Master node — DMA Tx FSM (concept scheme)
Enables DMA Tx channel request
(DMAERQH,DMAERQL)
!DTF & !DRF &
(LIN Idle !DBEF) &DMA_TEN &
!Token_DMA_Rx ?
DMA Tx transfer (Req/Ack minor/major loop) from
RAM area to LINFlexD regs
DMA Tx transfer is completed?
False
Set HTRQ to transmit the LIN frame
True (Rx mode)
True
(end of frame)
DTF cleared by SW?
DocID027809 Rev 4
Clear DTF
True
True
DBEF?
(header +[data])
!DIR & !DDRQ
False (Tx mode)
False
DTF?
False
True
Clear DTF
False
False
True
Clear DBEF to transmit the LIN frame
(data for extended frame)
False
DBEF?
True(extended frame
size > 8 bytes)
Figure
LINFlexD
833.
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