User Manual
BCM1250/BCM1125/BCM1125H
10/21/02
B r o a d c o m C o r p o r a t i o n
Document
1250_1125-UM100CB-R
Section 9: Ethernet MACs Page
305
Table 177: MAC Enable Registers
mac_enable_0 -
00_1006_4400
mac_enable_1 -
00_1006_5400
mac_enable_2 -
00_1006_6400
This register is used in both Ethernet and Packet FIFO modes
Bits
Name
Default
Description
1:0
rxdma_en
2'b0
Receive DMA channel enable. Must be set to enable a channel.
Bit 0 corresponds to channel 0, bit 1 to channel 1.
3:2 reserved 2'b0
Reserved
5:4
txdma_en
2'b0
Transmit DMA channel enable. Must be set to enable a channel.
Bit 4 corresponds to channel 0, bit 5 to channel 1.
7:6 reserved 2'b0
Reserved
8
p_reset
1'b0
Port reset. Writing a 1 to this bit will reset the entire MAC and Packet FIFO interface as
though it had come out of a system reset. All registers are restored to their default values
thus disabling and resetting the DMA engines, Ethernet mode logic and Packet FIFO
logic. The default for this bit is zero, so it will self-clear as part of the reset sequence.
9
reserved
1'b0 Reserved
10
mac_rx_en
1'b0
If this bit is clear the receive Ethernet media access engine will be held in reset. If this
bit is set it will run normally.
11
mac_tx_en
1'b0
If this bit is clear the transmit Ethernet media access engine will be held in reset. If this
bit is set it will run normally.
12
byp_rx_en
1'b0
If this bit is clear the receive Packet FIFO engine will be held in reset. If this bit is set it
will run normally.
13
byp_tx_en
1'b0
If this bit is clear the transmit Packet FIFO engine will be held in reset. If this bit is set it
will run normally.
63:14 reserved 50'b0
Reserved
Table 178: MAC Transmit DMA Control Register
mac_txd_ctl_0 -
00_1006_4420
mac_txd_ctl_1 -
00_1006_5420
mac_txd_ctl_2 -
00_1006_6420
This register is used in both Ethernet and Packet FIFO modes
Bits
Name
Default
Description
3:0
weight_ch0
4'b0
Transmit channel 0 round robin weight. Note that if both channels are enabled with weight
zero (the default) then no packets will be transmitted.
7:4
weight_ch1
4'b0
Transmit channel 1 round robin weight. See note above.
63:8 reserved
56'b0
Reserved