DM9620 DAVICOM [Davicom Semiconductor, Inc.], DM9620 Datasheet - Page 20

• Manufacturer Part Number: DM9620
• Description: USB2.0 to 10/100M Fast Ethernet Controller
• Manufacturer: DAVICOM [Davicom Semiconductor, Inc.]

4.7 Back Pressure Threshold Register (08H)
4.8 Flow Control Threshold Register ( 09H )
Preliminary
Version: DM9620 -15-DS-P02
February 20, 2012
7:4
3:0
7:4
3:0
Bit
Bit
BPHW
HWOT
LWOT
Name
Name
JPT
PHS3h, RW
PHS7h, RW
PHS3h, RW
PHS8h, RW
Default
Default
Back Pressure High Water Overflow Threshold. MAC will generate the jam
pattern when RX SRAM free space is lower than this threshold value.
Default is 3K-byte free space. Please don’t exceed SRAM size.
(1 unit=1K bytes)
Jam Pattern Time. Default is 100us.
bit3 bit2 bit1 bit0
RX FIFO High Water Overflow Threshold
Send a pause packet with pause_time=FFFFH when the RX RAM free space is
less than this value., If this value is zero, its meaning is no free RX SARM space.
Default is 3K-byte free space. Please don’t exceed SRAM size.
(1 unit=1K bytes)
RX FIFO Low Water Overflow Threshold
Send a pause packet with pause_time=0000 when RX SARM free space is
larger than this value. This pause packet is enabled after high water pause
packet transmitted. Default SRAM free space is 8K-byte. Please don’t exceed
SRAM size.
(1 unit=1K bytes)
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
time
2.5us
5us
7.5us
12.5us
25us
50us
75us
100us
125us
150us
175us
200us
2250us
250us
275us
300us
Description
Description
USB2.0 to Fast Ethernet Controller
DM9620
20