MSI-X Plumbing
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 259
Clear Interrupt, Mask Interrupt, Mask Mode (0x68[0], 0x68[1], 0x68[8])
These bits have no effect on MSI-X operations.
Clear Ticks On Rx Bd Events Mode (0x3c00[9])
Enabled by setting the Clear Ticks mode on Rx bit of the Host Coalescing Mode register. When enabled, the
counters initialize to the idle state and begin counting only after a receive BD event is detected. This register bit
also applies to all newly created RCTR Registers.
No Interrupt On Force Update (0x3c00[11])
Enabled by setting the No Interrupt on Force bit of the Host Coalescing Mode register. After enabling this bit,
subsequent writes to the Coalesce Now bit(s) of the Host Coalescing Mode register cause status block
update(s) without the corresponding interrupt event. This bit applies to all MSI-X vectors and respective Status
Blocks.
No Interrupt On DMAD Force (0x3c00[12])
Enabled by setting the No Interrupt on DMAD force bit of the Host Coalescing Mode register. When enabled,
the BD_FLAG_COAL_NOW bit of the buffer descriptor may be set to force a status block update without a
corresponding interrupt. This feature is associated to Send BDs only; hence, it applies to Vector#0 in MSI-X
mode when Multiple Send Queues are not enabled.
Register Transfer Level (RTL) Note: The HC RTL honors the Coal_Now Flag coming from both Send or Receive
flow-through queues (FTQs). Rx FTQ never requests it, as the RBDs do not support any such flag.
Do Not Interrupt On Receives (0x6800[14])
If set, an interrupt is not generated upon a Receive Return Ring producer update. This bit applies equally to
vector#0 through vector#16 in Multivector mode.