Chapter 12: 10/100 IEEE802.3 Media Access Controller
TX7901 User’s Manual (Rev. 6.30T – Nov, 2001)
12-48
register are put in the frame Descriptor after each frame datum has been transferred into
memory.
Second, event counters are updated based on the status at the end of a receive frame.
These counters can be read at any time.
12.5.2.4.5
Undersized and Fragment Rejection
A frame is received that is less than 64 bytes and has a good CRC (undersized), has a bad
CRC, or frame alignment error (fragment). This kind of frame can be filtered if RxSOFTh is
set to 64 bytes or more.
12.5.2.4.6 Error
Conditions
Error conditions can be found in the Frame Interrupt Register.
12.5.2.4.7 Overflow
When the RxFIFO overflows, the interrupt bit RFIFO is set. The receiver will ignore all
subsequent data from that frame. If the flow control enable bit (RxFCEn) is set, the MAC will
send out a flow control frame while configured for full-duplex. It will force a collision each
time CRS is asserted while configured for half-duplex.
12.5.2.4.8 Enabling
The port must be enabled before the MAC receives any frame. If the port is disabled by
clearing the enable bit in RFCReg and a frame is currently being received, the port is
disabled after the frame is fully received.
Summary of Contents for TMPR7901
Page 1: ...TX System RISC TX79 Family TMPR7901 Symmetric 2 way superscalar 64 bit CPU ...
Page 14: ...Handling Precautions ...
Page 15: ......
Page 17: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 41: ...4 Precautions and Usage Considerations 4 2 ...
Page 42: ...TX7901 User s Manual Rev 6 30T November 2001 DOCUMENT NUMBER M 99 00004 07 ...
Page 43: ......
Page 259: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 1 13 Removed ...
Page 260: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 2 ...