Maxim Integrated DS33R11 - Manual (Page 181)

DS33R11 Ethernet Mapper with Integrated T1/E1/J1 Transceiver
181 of 344
Register Name: SU.RFSB0
Register Description: Receive Frame Status Byte 0
Register Address: 154h
Bit
# 7 6 5 4 3 2 1 0
Name FL7 FL6 FL5 FL4 FL3 FL2 FL1 FL0
Default 0 0 0 0 0 0 0 0
Bits 0 - 7: Frame Length (FL[0:7]) These 8 bits are the low byte of the length (in bytes) of the received frame,
with FCS and Padding. If Automatic Pad Stripping is enabled, this value is the length of the received packet without
PCS or Pad bytes. The upper 6 bits are contained in SU.RFSB1.
Register Name:
SU.RFSB1
Register Description: Receive Frame Status Byte 1
Register Address: 155h
Bit
# 7 6 5 4 3 2 1 0
Name RF WT FL13 FL12 FL11 FL10 FL9 FL8
Default 0 0 0 0 0 0 0 0
Bit 7: Runt Frame (RF) This bit is set to 1 if the received frame was altered by a collision or terminated within the
collision window.
Bit 6: Watchdog Timeout (WT) This bit is set to 1 if a packet receive time exceeds 2048 byte times. After 2048
byte times the receiver is disabled and the received frame will fail CRC check.
Bits 0-5: Frame Length (FL[8:13]) These 6 bits are the upper bits of the length (in bytes) of the received frame,
with FCS and Padding. If Automatic Pad Stripping is enabled, this value is the length of the received packet without
PCS or Pad bytes.
Register Name:
SU.RFSB2
Register Description: Receive Frame Status Byte 2
Register Address: 156h
Bit
# 7 6 5 4 3 2 1 0
Name - - CRCE DB MIIE FT CS FTL
Default 0 0 0 0 0 0 0 0
Bit 5: CRC Error (CRCE) This bit is set to 1 if the received frame does not contain a valid CRC value.
Bit 4: Dribbling Bit (DB) This bit is set to 1 if the received frame contains a noninteger multiple of 8 bits. It does
not indicate that the frame is invalid. This bit is not valid for runt or collided frames.
Bit 3: MII Error (MIIE) This bit is set to 1 if an error was found on the MII bus.
Bit 2: Frame Type (FT) This bit is set to 1 if the received frame exceeds 1536 bytes. It is equal to zero if the
received frame is an 802.3 frame. This bit is not valid for runt frames.
Bit 1: Collision Seen (CS) This bit is set to 1 if a late collision occurred on the received packet. A late collision is
one that occurs after the 64 byte collision window.
Bit 0: Frame Too Long (FTL) This bit is set to 1 if a frame exceeds the 1518 byte maximum standard Ethernet
frame. This bit is only an indication, and causes no frame truncation.