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R01UH0336EJ0102 Rev.1.02
Page 237 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 5 DMA Module
5.6.7
Error Responses
(1)
Error Response Leading to Suspension of DMA Transfer
When an error occurs at the DMA transfer source or transfer destination,
DMAC sets the DMA transfer abort bit (DTRC0ADS) of the DMA transfer
request control register (DTRC0) to suspend subsequent DMA transfer. At the
same time, the DMA transfer error status bit (DTRC0ERR) is set and a
SysError exception is generated for the CPU. Once the user has confirmed
that DTRC0ERR has been set, the DMA transfer error flag (DTSnER) of the
DMA transfer status register (DTSn) can be used to identify the channel where
the error occurred.
In this case, note that if the error response is acknowledged within the read
cycle, the write cycle does not proceed but the transfer address and transfer
count are updated.
(2)
Canceling Transfer Suspension Due to Error Response
DMA transfer suspension can be reversed by clearing the DMA transfer abort
bit (DTRC0ADS) and DMA transfer error status bit (DTRC0ERR) of the DMA
transfer request control register (DTRC0).
Clear the DMA transfer enable bit (DTSnDTE) of the DMA transfer status
register (DTSn) in advance, so that DMA transfer is not resumed after reversal
of suspension. In the case of a software DMA transfer request, also clear the
software DMA transfer request bit (DTSnSR).
Содержание V850 Series
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