Texas Instruments AM335 Series Technical Reference Manual

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14.5.2.9 DMASTATUS Register (offset = 24h) [reset = 0h]
DMASTATUS is shown in Figure 14-37 and described in Table 14-48.
CPDMA_REGS CPDMA STATUS REGISTER
Figure 14-37. DMASTATUS Register
31 30 29 28 27 26 25 24
IDLE Reserved
R-0h R-0h
23 22 21 20 19 18 17 16
TX_HOST_ERR_CODE Reserved TX_ERR_CH
R-0h R-0h R-0h
15 14 13 12 11 10 9 8
RX_HOST_ERR_CODE Reserved RX_ERR_CH
R-0h R-0h R-0h
7 6 5 4 3 2 1 0
Reserved
R-0h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 14-48. DMASTATUS Register Field Descriptions
Bit Field Type Reset Description
31 IDLE R 0h Idle Status Bit - Indicates when set that the CPDMA is not
transferring a packet on transmit or receive.
30-24 Reserved R 0h
23-20 TX_HOST_ERR_CODE R 0h TX Host Error Code - This field is set to indicate CPDMA detected
TX DMA related host errors.
The host should read this field after a HOST_ERR_INT to determine
the error.
Host error Interrupts require hardware reset in order to recover.
A zero packet length is an error, but it is not detected.
0000 - No error
0001 - SOP error.
0010 - Ownership bit not set in SOP buffer.
0011 - Zero Next Buffer Descriptor Pointer Without EOP
0100 - Zero Buffer Pointer.
0101 - Zero Buffer Length
0110 - Packet Length Error (sum of buffers is less than packet
length)
0111 - reserved ...
1111 - reserved
19 Reserved R 0h
18-16 TX_ERR_CH R 0h TX Host Error Channel - This field indicates which TX channel (if
applicable) the host error occurred on.
This field is cleared to zero on a host read.
000 - The host error occurred on TX channel 0 ...
111 - The host error occurred on TX channel 7
15-12 RX_HOST_ERR_CODE R 0h RX Host Error Code - This field is set to indicate CPDMA detected
RX DMA related host errors.
The host should read this field after a HOST_ERR_INT to determine
the error.
Host error Interrupts require hardware reset in order to recover.
0000 - No error
0001 - reserved
0010 - Ownership bit not set in input buffer.
0011 - reserved
0100 - Zero Buffer Pointer.
0101 - Zero buffer length on non-SOP descriptor
0110 - SOP buffer length not greater than offset ...
1111 - reserved
1267
SPRUH73H–October 2011–Revised April 2013 Ethernet Subsystem
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Texas Instruments AM335 Series Specifications

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Brand	Texas Instruments
Model	AM335 Series
Category	Computer Hardware
Language	English