Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

Bits

0

1

2

3

4

5

6

7

8

9

10

11

 

12

13

14

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Field

 

 

 

Ñ

 

 

 

X_DES_ACTIVE

 

 

 

 

Ñ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

 

 

 

 

 

 

0000_0000_0000_0000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

Read/write

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Addr

 

 

 

 

 

 

 

0xE54

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bits

16

17

18

19

20

21

22

23

24

25

26

27

 

28

29

30

31

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Field

 

 

 

 

 

 

 

Ñ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

 

 

 

 

 

 

0000_0000_0000_0000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

Read/write

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Addr

 

 

 

 

 

 

 

0xE56

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 6-12. X_DES_ACTIVE Register

Table 6-13 describes X_DES_ACTIVE Þelds.

Table 6-13. X_DES_ACTIVE Field Descriptions

Bits

Name

Description

 

 

 

0Ð6

Ñ

Reserved.

 

 

 

7

X_DES_ACTIVE

Set when this register is written, regardless of the value written. Cleared whenever no

 

 

additional ready descriptors remain in the transmit ring.

 

 

 

8Ð31

Ñ

Reserved.

 

 

 

6.2.13 MII Management Frame Register (MII_DATA)

The MII_DATA register, shown in Figure 6-13, is used to communicate with the attached MII-compatible PHY device, providing read/write access to their MII registers. Writing to MII_DATA causes a management frame to be sourced unless MII_SPEED was cleared; in this case, if MII_SPEED is then written to a non-zero value and an MII frame is generated with the data previously written to MII_DATA. This allows MII_DATA and MII_SPEED to be programmed in either order if MII_SPEED is currently zero. MII_DATA is accessed by the user and does not reset to a deÞned value.

6-12MPC860T (Rev. D) Fast Ethernet Controller Supplement MOTOROLA

PRELIMINARYÑSUBJECTFor ore nformationTO CHANGEOn ThisWITHOUTProduct,NOTICE

Go to: www.freescale.com

Page 44
Image 44
Freescale Semiconductor MPC860T user manual MII Management Frame Register Miidata, describes Xdesactive Þelds