RM0082
HS_Media independent interface (MII)
Doc ID 018672 Rev 1
537/844
field greater than or equal to 1501 bytes will be passed to the application without
stripping the Pad/FCS field.
Clearing this bit, the MAC will pass unmodified all incoming frames to the application.
●
BL
This 2 bit field represents the back-off limit which determines the random integer
number (r) of slot time delays (that is., 512 bit times) the MAC waits before
rescheduling a transmission attempt during retries after a collision.
The random integer r takes value ranging from 0 to 2k (2k not included), being k
specified by BL field according to encoding below:
Note:
1
where n is the number of retransmission attempts.
2
This bit is applicable only to half-duplex mode and it is reserved (RO) in full-duplex only
configuration.
●
DC
Setting this bit, the deferral check function is enabled in the MAC. The MAC will issue a
Frame Abort status, along with the excessive deferral error bit set in the transmit frame
status when transmit state machine is deferred for more than 24 288 bit times.
Note:
This bit is applicable only to half-duplex mode and it is reserved (RO) in full-duplex only
configuration.
●
TE
Setting this bit, transmit state machine of the MAC is enabled for transmission on the
MII. Otherwise, transmit state machine is disabled after the completion of the
transmission of the current frame, and will not transmit any further frames.
●
RE
Setting this bit, receive state machine of the MAC is enabled for receiving frames from
the MII. Otherwise, receive state machine is disabled after the completion of the
reception of the current frame, and will not receive any further frames.
24.7.17
MAC frame filter register (Register1, MAC)
The MAC frame filter is a register which contains the filter controls for receiving frames. The
MAC frame filter bit assignments are given in
Note:
The 1
st
level of filtering is performed going to the address check block of the MAC (address
filtering). The 2
nd
level of filtering is performed on the incoming frame, based on other
controls such as ‘pass bad frames’ or ‘pass control frames’.
Table 445.
BL field bit assignments
Value
K
2‘b00
min (n,10)
2‘b01
min (n,8)
2‘b10
min (n,4)
2‘b11
min(n,1)