Ethernet Subsystem Registers
14.5.2.8 DMACONTROL Register (offset = 20h) [reset = 0h]
DMACONTROL is shown in
and described in
CPDMA_REGS CPDMA CONTROL REGISTER
Figure 14-36. DMACONTROL Register
31
30
29
28
27
26
25
24
Reserved
R-0h
23
22
21
20
19
18
17
16
Reserved
R-0h
15
14
13
12
11
10
9
8
TX_RLIM
R/W-0h
7
6
5
4
3
2
1
0
Reserved
RX_CEF
CMD_IDLE
RX_OFFLEN_BLOCK
RX_OWNERSHIP
TX_PTYPE
R-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 14-47. DMACONTROL Register Field Descriptions
Bit
Field
Type
Reset
Description
31-16
Reserved
R
0h
15-8
TX_RLIM
R/W
0h
Transmit Rate Limit Channel Bus
00000000 - no rate-limited channels
10000000 - channel 7 is rate-limited
11000000 - channels 7 downto 6 are rate-limited
11100000 - channels 7 downto 5 are rate-limited
11110000 - channels 7 downto 4 are rate-limited
11111000 - channels 7 downto 3 are rate-limited
11111100 - channels 7 downto 2 are rate-limited
11111110 - channels 7 downto 1 are rate-limited
11111111 - channels 7 downto 0 are rate-limited all others invalid -
this bus must be set msb towards lsb.
tx_ptype must be set if any tx_rlim bit is set for fixed priority.
7-5
Reserved
R
0h
4
RX_CEF
R/W
0h
RX Copy Error Frames Enable - Enables DMA overrun frames to be
transferred to memory (up to the point of overrun).
The overrun error bit will be set in the frame EOP buffer descriptor.
Overrun frame data will be filtered when rx_cef is not set.
Frames coming from the receive FIFO with other error bits set are
not effected by this bit.
0 - Frames containing overrun errors are filtered.
1 - Frames containing overrun errors are transferred to memory.
3
CMD_IDLE
R/W
0h
Command Idle
0 - Idle not commanded
1 - Idle Commanded (read idle in DMAStatus)
2
RX_OFFLEN_BLOCK
R/W
0h
Receive Offset/Length word write block.
0 - Do not block the DMA writes to the receive buffer descriptor
offset/buffer length word.
The offset/buffer length word is written as specified in CPPI 3.0.
1 - Block all CPDMA DMA controller writes to the receive buffer
descriptor offset/buffer length words during CPPI packet processing.
when this bit is set, the CPDMA will never write the third word to any
receive buffer descriptor.
1265
SPRUH73H – October 2011 – Revised April 2013
Ethernet Subsystem
Copyright © 2011–2013, Texas Instruments Incorporated