NEC Network Controller uPD98502 - Manual (Page 287)

CHAPTER 5 ETHERNET CONTROLLER
Preliminary User’s Manual S15543EJ1V0UM 287
5.2.6 En_CLRT (Collision Register)
Bits Field R/W Default Description
31:14 Reserved R/W 0 Reserved for future use. Write 0s.
13:8 LCOL R/W 38H Late collision window:
This field sets collision window size.
The formula for the collision window size is:
collision window size = (LCOL + 8) × 8 bits time
7:4 Reserved R/W 0 Reserved for future use. Write 0s.
3:0 RETRY R/W 0FH Maximum number of retry:
This field sets the maximum number of retries during the transmission. If a
retry occurs beyond this value, the current transmission is aborted.
5.2.7 En_LMAX (Maximum Packet Length Register)
Bits Field R/W Default Description
31:16 Reserved R/W 0 Reserved for future use. Write 0s.
15:0 MAXF R/W 600H Maximum packet length:
This field sets the maximum length of transmit and receive packet by the
octet when HUGEN bit in En_MACC1 register is set to a ‘0’.
Receive: If the current receive packet length is greater than the value of
MAXF, MAC Control Block terminates the reception.
Transmit: If the current transmit packet length is greater than the value of
MAXF, MAC Control Block aborts the transmission.
5.2.8 En_RETX (Retry Count Register)
Bits Field R/W Default Description
31:4 Reserved R/W 0 Reserved for future use. Write 0s.
3:0 RETX R/W 0 Retry counter:
This field indicates the number of the retries during the current transmission.
5.2.9 En_LSA2 (Station Address Register 2)
Bits Field R/W Default Description
31:16 Reserved R/W 0 Reserved for future use. Write 0s.
15:0 LSA2 R/W 0 Station address SA (47:32). Please refer to 5.3.6.
5.2.10 En_LSA1 (Station Address Register 1)
Bits Field R/W Default Description
31:0 LSA1 R/W 0 Station address SA (31:0):
This field sets the station address. The station address: SA (47:0) is used by
the MAC Control Block as the source address in the PAUSE control frame,
and used for the comparison with the destination address of a received
packet. Please refer to 5.3.6.