Freescale Semiconductor MPC860T Beginning of RxBD Ring Rdesstart, Describes Hashtablelow Þelds

Models: MPC860T

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Freescale Semiconductor, Inc.

 

 

Freescale Semiconductor, Inc.

Table 6-5 describes HASH_TABLE_LOW Þelds.

 

 

Table 6-5. HASH_TABLE_LOW Field Descriptions

 

 

 

Bits

Name

Description

 

 

 

0Ð31

HASH_LOW

Contains the lower 32 bits of the 64-bit hash table used in address recognition for receive

 

 

frames with a multicast address. HASH_LOW[0] contains hash index bit 31. HASH_LOW[31]

 

 

contains hash index bit 0.

 

 

 

6.2.5 Beginning of RxBD Ring (R_DES_START)

The R_DES_START register, shown in Figure 6-5, is like the RBASE register used by other protocols. It provides a pointer to the start of the circular RxBD queue in external memory. This pointer should be quad-word aligned. Bits 30 and 31 should be written to 0 by the user; hardware ignores non-zero values in these bits. This register is written by the user, is not reset, and must be initialized by the user.

Bits

0

1

2

3

4

5

 

6

 

7

 

8

 

9

10

11

12

13

14

 

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Field

 

 

 

 

 

 

 

 

R_DES_START

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

 

 

 

 

 

 

 

 

UndeÞned

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

 

 

Read/write

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Addr

 

 

 

 

 

 

 

 

 

0xE10

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bits

16

17

18

19

20

21

 

22

 

23

 

24

 

25

26

27

28

29

30

 

31

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Field

 

 

 

 

 

 

R_DES_START

 

 

 

 

 

 

 

 

00

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

 

 

 

 

 

 

 

 

UndeÞned

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

 

 

Read/write

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Addr

 

 

 

 

 

 

 

 

 

0xE12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 6-5. R_DES_START Register

Table 6-6 describes R_DES_START Þelds.

Table 6-6. R_DES_START Field Descriptions

Bits

Name

Description

 

 

 

0Ð29

R_DES_START

Pointer to start of RxBD queue.

 

 

 

30Ð31

Ñ

Reserved. Should be written to zero by the host processor.

 

 

 

6.2.6 Beginning of TxBD Ring (X_DES_START)

The X_DES_START register, shown in Figure 6-6, is like the TBASE register used by other protocols. It provides a pointer to the start of the circular TxBD queue in external memory. This pointer should be quad-word aligned. Bits 30 and 31 should be cleared by the user; hardware ignores non-zero values in these bits. It is written by the user, is not reset, and must be initialized by the user.

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Freescale Semiconductor MPC860T user manual Beginning of RxBD Ring Rdesstart, Beginning of TxBD Ring Xdesstart