Programming Model

Table 17-21. RCR Field Descriptions (continued)

Bits

Name

Description

 

 

 

1

DRT

Disable receive on transmit.

 

 

0 Receive path operates independently of transmit (use for

 

 

full duplex or to monitor transmit activity in half duplex

 

 

mode).

 

 

1 Disable reception of frames while transmitting (normally

 

 

used for half duplex mode).

 

 

 

0

LOOP

Internal loopback. If set, transmitted frames are looped back

 

 

internal to the device and the transmit output signals are not

 

 

asserted. The system clock is substituted for the ETXCLK

 

 

when LOOP is asserted. DRT must be set to zero when

 

 

asserting LOOP.

 

 

 

17.5.4.10 Transmit Control Register (TCR)

The TCR is read/write and is written by the user to configure the transmit block. This register is cleared at system reset. Bits 2 and 1 should be modified only when ECR[ETHER_EN] = 0.

 

31

 

 

 

 

 

 

16

Field

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

0000_0000_0000_0000

 

 

 

 

 

 

 

 

 

 

 

R/W

 

R/W

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

Field

 

 

RFC_PAUSE

TFC_PAUSE

FDEN

HBC

GTS

 

 

 

 

 

 

 

 

Reset

 

0000_0000_0000_0000

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

R/W

 

 

R

 

R/W

 

 

 

 

 

 

 

 

 

 

Address

 

IPSBAR + 0x10C4

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 17-13. Transmit Control Register (TCR)

17-34

MCF5282 User’s Manual

MOTOROLA

Page 390
Image 390
Motorola MCF5282, MCF5281 user manual Transmit Control Register TCR, Tfcpause Fden, Gts