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 10: Serial Interfaces Page
355
Table 234: Serial Write Threshold Register
ser_tx_wr_thres_0 -
00_1006_0568
ser_tx_wr_thres_1 -
00_1006_0968
Bits
Name
Default
Description
3:0
thrsh
4’b100
Number of free 64 bit entries the TxFIFO must have before it signals the DMA that space
is free. This must be set to 4 for normal operation. Writing other values in this register is
for Broadcom Use Only.
15:4
reserved
12’b0
Reserved
63:16
notimp
48’bx
Not implemented.
Table 235: Serial Transmit Read Threshold Register
ser_tx_rd_thres_0 -
00_1006_0560
ser_tx_rd_thres_1 -
00_1006_0960
Bits
Name
Default
Description
3:0
thrsh
4’b100
Number of filled 64 bit entries the TxFIFO must have before the protocol engine will start
transmitting the frame. The FIFO is only 8 entries, so setting bit [3] will result in
UNPREDICTABLE behaviou
r.
15:4
reserved
12’b0
Reserved
63:16
notimp
48’bx
Not implemented.
Table 236: Serial Receive Read Threshold Register
ser_rx_rd_thres_0 -
00_1006_0570
ser_rx_rd_thres_1 -
00_1006_0970
Bits
Name
Default
Description
3:0
thrsh
4’b1000
Number of valid 32 bit entries the RxFIFO must have before it signals the DMA to
read data. This must be set to 8 for normal operation.
15:4
reserved
12’b0
Reserved
63:16
notimp
48’bx
Not implemented.
Table 237: Serial Minimum Frame Size Register
ser_minfrm_sz_0 -
00_1006_0508
ser_minfrm_sz_1 -
00_1006_0908
Bits
Name
Default
Description
15:0
size
16’b0
Minimum frame size in bytes.
63:16
notimp
48’bx
Not implemented.