Intel PCI User Manual

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306
Software Developer’s Manual
Register Descriptions
When this timer is enabled, a separate absolute countdown timer is initiated upon successfully 
receiving each packet to system memory. When this absolute timer expires, pending receive 
descriptor writebacks are flushed and a receive timer interrupt is generated.
Setting this register to 0b disables the absolute timer mechanism (the RDTR register should be 
used with a value of 0b to cause immediate interrupts for all receive packets).
Receive interrupts due to a Receive Packet Timer (RDTR) expiration cancels a pending RADV 
interrupt. If enabled, the RADV countdown timer is reloaded but halted, so as to avoid generation 
of a spurious second interrupt after the RDTR has been noted. 
13.4.32
Receive Small Packet Detect Interrupt
1
RSRPD (02C00h; R/W)
13.4.33
Transmit Control Register
TCTL (00400h;R/W)
This register controls all transmit functions for the Ethernet controller.
1.
Not applicable to the 82544GC/EI.
31                                                                    12
11                                                           0
Reserved
SIZE
Field
Bit(s)
Initial 
Value
Description
SIZE
11:0
0b
If the interrupt is enabled, any receive packet of size 
≤ SIZE asserts 
an Interrupt. SIZE is specified in bytes and includes the headers and 
the CRC. It does not include the VLAN header in size calculation if it 
is stripped.
Reserved
31:12
X
Reserved. Reads as 0b.