Initialization Procedure
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 142
25.
Configure the Message Transfer Unit MTU size. The MTU sets the upper boundary on RX packet size;
packets larger than the MTU are marked oversized and discarded by the RX MAC. The MTU bit field in the
Receive MTU Size register (see
“Receive MTU Size Register (offset: 0x43C)” on page 316
) must be
configured before RX traffic is accepted. Host software must account for the following variables when
calculating the MTU:
• VLAN TAG
• CRC
• Jumbo Frames Enabled
26.
Configure the Inter-Packet Gap (IPG) for transmit by setting the Transmit MAC Lengths register (see
“Transmit MAC Lengths Register (offset: 0x464)” on page 321
). The register contains three bit fields:
IPG_CRS_Length, IPG_Length, and Slot_Time_Length. The value 0x2620 should be written into this
register.
27.
Configure the default RX return ring for non-matched packets. The MAC has a rules checker, and packets
do not always have a positive match. For this situation, host software must specify a default ring, where the
RX packet is placed. The bit field is located in the Receive Rules Configuration register (see
Configuration Register (offset: 0x500)” on page 326
28. .
Configure the number of Receive Lists. The Receive List Placement Configuration register (see
List Placement Configuration Register (offset: 0x2010)” on page 358
) allows host software to initialize QOS
rules checking. For example, a value of 0x181 (as used by Broadcom drivers) breaks down as follows:
• One interrupt distribution list
• Sixteen active lists
• One bad frames class
29.
Write the Receive List Placement Statistics mask. Broadcom drivers write a value of 0x7BFFFF (24 bits) to
the Receive List Placement Stats Enable Mask register (see
“Receive List Placement Statistics Enable Mask
Register (offset: 0x2018)” on page 359
30.
Enable RX statistics by asserting the Statistics_Enable bit in the Receive List Placement Control register
(see
“Receive List Placement Statistics Control Register (offset: 0x2014)” on page 359
).
31.
Enable the Send Data Initiator mask by writing 0xFFFFFF (24 bits) to the Send Data Initiator Enable Mask
register (see
“Send Data Initiator Statistics Mask Register (offset: 0xC0C)” on page 346”
).
32.
Enable TX statistics by asserting the Statistics_Enable and Faster_Statistics_Update bits in the Send Data
Initiator Control register (0x0C08)
33.
Disable the host coalescing engine by writing 0x0000 to the Host Coalescing Mode register (see
Coalescing Mode Register (offset: 0x3C00)” on page 413
). Software needs to disable the host coalescing
engine before configuring its parameters.
34.
Poll 20 ms for the host coalescing engine to stop. Read the Host Coalescing Mode register (see
Coalescing Mode Register (offset: 0x3C00)” on page 413
) and poll for 0x0000.
Note:
An incorrectly configured IPG introduces far end receive errors on the MAC’s link partner.