PXN20RM Datasheet, PDF (531/1376 Pages) Freescale Semiconductor, Inc – PXN20 Microcontroller

Enhanced Direct Memory Access Controller (eDMA)
The occurrence of any type of error causes the DMA engine to stop the active channel and the appropriate
channel bit in the eDMA error register to be asserted. At the same time, the details of the error condition
are loaded into the EDMA_ESR. The major loop complete indicators, setting the transfer control
descriptor DONE flag and the possible assertion of an interrupt request, are not affected when an error is
detected. After the error status has been updated, the DMA engine continues to operate by servicing the
next appropriate channel. A channel that experiences an error condition is not automatically disabled. If a
channel is terminated by an error and then issues another service request before the error is fixed, that
channel will execute and terminate with the same error condition.
Offset: EDMA_BASE + 0x0004
Access: User read-only
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R VLD 0
0
0
0
0
0
0
0
0
0
0
0
0
0 ECX
W
Reset 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
17
R GPE CPE
W
Reset 0
0
18
19
20
21
22
23
24
25
26
27
28
29
30
31
ERRCHN
SAE SOE DAE DOE NCE SGE SBE DBE
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 24-3. eDMA Error Status Register (EDMA_ESR)
Table 24-4. EDMA_ESR Field Descriptions
Field
VLD
ECX
GPE
CPE
ERRCHN
Description
Valid Bit. Logical OR of all EDMA_ERL status bits.
0 No EDMA_ER bits are set.
1 At least one EDMA_ER bit is set indicating a valid error exists that has not been cleared.
Transfer canceled.
0 No canceled transfers.
1 The last recorded entry was a canceled transfer via the error cancel transfer input.
Group-priority error.
0 No group-priority error.
1 The last recorded error was a configuration error among the group priorities indicating not all group priorities
are unique.
Channel-Priority Error.
0 No channel-priority error.
1 The last recorded error was a configuration error in the channel priorities within a group, indicating not all
channel priorities within a group are unique.
Error Channel Number or Canceled Channel Number. Channel number of the last recorded error (excluding
GPE and CPE errors) or last recorded transfer that was error cancelled.
Note: Do not rely on the number in the ERRCHN field group for channel-priority errors. Group- and
Channel-priority errors must be resolved by inspection. The application code must interrogate the priority
registers to find groups or channels with duplicate priority level.
Freescale Semiconductor
PXN20 Microcontroller Reference Manual, Rev. 1
24-11