High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface

Datasheet

14.5.2.23Port x MAC Transmit Configuration Register (MAC_TX_CFG_x)

Register #:

Port0: 0440h

Size:

32 bits

 

Port1:

0840h

 

 

 

Port2:

0C40h

 

 

This read/write register configures the transmit packet parameters of the port.

BITS

DESCRIPTION

TYPE

DEFAULT

 

 

 

 

31:8

RESERVED

RO

-

 

 

 

 

7

MAC Counter Test

R/W

0b

 

When set, TX and RX counters that normally clear to 0 when read, will be

 

 

 

set to 7FFF_FFFCh when read with the exception of the Port x MAC

 

 

 

Receive Packet Length Count Register (MAC_RX_PKTLEN_CNT_x), Port x

 

 

 

MAC Transmit Packet Length Count Register (MAC_TX_PKTLEN_CNT_x),

 

 

 

and Port x MAC Receive Good Packet Length Count Register

 

 

 

(MAC_RX_GOODPKTLEN_CNT_x) counters which will be set to

 

 

 

7FFF_FF80h.

 

 

 

 

 

 

6:2

IFG Config

R/W

10101b

 

These bits control the transmit inter-frame gap.

 

 

 

IFG bit times = (IFG Config *4) + 12

 

 

 

 

 

 

1

TX Pad Enable

R/W

1b

 

When set, packets shorter than 64 bytes are padded with zeros if needed

 

 

 

and a FCS is appended. Packets that are 60 bytes or less will become 64

 

 

 

bytes. Packets that are 61, 62, and 63 bytes will become 65, 66, and 67

 

 

 

bytes respectively.

 

 

 

 

 

 

0

TX Enable

R/W

1b

 

When set, the transmit port is enabled. When cleared, the transmit port is

 

 

 

disabled.

 

 

 

 

 

 

Revision 1.4 (08-19-08)

344

SMSC LAN9312

 

DATASHEET