BCM1250/BCM1125/BCM1125H
User Manual
10/21/02
B r o a d c o m C o r p o r a t i o n
Page
166
Section 7: DMA
Document
1250_1125-UM100CB-R
Table 93: Ethernet and Serial DMA Descriptor Base Address Register
dma_dscr_base_mac_0_rx_ch_0 -
00_1006_4810
dma_dscr_base_mac_0_tx_ch_0 -
00_1006_4C10
dma_dscr_base_mac_0_rx_ch_1 -
00_1006_4910
dma_dscr_base_mac_0_tx_ch_1 -
00_1006_4D10
dma_dscr_base_mac_1_rx_ch_0 -
00_1006_5810
dma_dscr_base_mac_1_tx_ch_0 -
00_1006_5C10
dma_dscr_base_mac_1_rx_ch_1 -
00_1006_5910
dma_dscr_base_mac_1_tx_ch_1 -
00_1006_5D10
dma_dscr_base_mac_2_rx_ch_0 -
00_1006_6810
dma_dscr_base_mac_2_tx_ch_0 -
00_1006_6C10
dma_dscr_base_mac_2_rx_ch_1 -
00_1006_6910
dma_dscr_base_mac_2_tx_ch_1 -
00_1006_6D10
dma_dscr_base_ser_0_rx -
00_1006_0410
dma_dscr_base_ser_0_tx -
00_1006_0490
dma_dscr_base_ser_1_rx -
00_1006_0810
dma_dscr_base_ser_1_tx -
00_1006_0890
Bits
Name
Default
Description
3:0
zero
4'b0
These bits must be zero.
39:4
base
36'b0
This is the base address of the descriptor ring, or the pointer to the first descriptor in a
chain. This register must only be changed when the channel is disabled. When a channel
is disabled and enabled again it will start fetching descriptors from this address.
64:40
reserved
24’b0
Reserved
Table 94: ASIC Mode Base Address
dma_asic_addr_mac_0 -
00_1006_4418
dma_asic_addr_mac_1 -
00_1006_5418
dma_asic_addr_mac_2 -
00_1006_6418
dma_asic_addr_ser_0 -
00_1006_0598
dma_asic_addr_ser_1 -
00_1006_0998
Bits
Name
Default
Description
19:0
zero
20'b0
These bits must be zero.
39:20
base
36'b0
This is the base of the ASIC address space.
64:40
reserved
24’b0
Reserved
Table 95: Descriptor Count Register
dma_dscr_cnt_mac_0_rx_ch_0 -
00_1006_4818
dma_dscr_cnt_mac_0_tx_ch_0 -
00_1006_4C18
dma_dscr_cnt_mac_0_rx_ch_1 -
00_1006_4918
dma_dscr_cnt_mac_0_tx_ch_1 -
00_1006_4D18
dma_dscr_cnt_mac_1_rx_ch_0 -
00_1006_5818
dma_dscr_cnt_mac_1_tx_ch_0 -
00_1006_5C18
dma_dscr_cnt_mac_1_rx_ch_1 -
00_1006_5918
dma_dscr_cnt_mac_1_tx_ch_1 -
00_1006_5D18
dma_dscr_cnt_mac_2_rx_ch_0 -
00_1006_6818
dma_dscr_cnt_mac_2_tx_ch_0 -
00_1006_6C18
dma_dscr_cnt_mac_2_rx_ch_1 -
00_1006_6918
dma_dscr_cnt_mac_2_tx_ch_1 -
00_1006_6D18
dma_dscr_cnt_ser_0_rx -
00_1006_0418
dma_dscr_cnt_ser_0_tx -
00_1006_0498
dma_dscr_cnt_ser_1_rx -
00_1006_0818
dma_dscr_cnt_ser_1_tx -
00_1006_0898
Bits
Name
Default
Description
15:0
count
16'b0
This is the number of descriptors owned by the DMA engine. Reads will return the number
of descriptors owned (Count in
and
). Data
that is written to this register will be added to the count (assigning that number of additional
descriptors to the controller). The count is a 16 bit unsigned number, there is no overflow
protection. Software should ensure it does not unintentionally cause the count to wrap.
64:16
reserved
48’b0
Reserved