Freescale Semiconductor MPC860T Receive Hash Register Rhash, describes Rcntrl Þelds, Bcrej

Models: MPC860T

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Freescale Semiconductor, Inc.

 

 

Freescale Semiconductor, Inc.

Table 6-22 describes R_CNTRL Þelds.

 

 

Table 6-22. R_CNTRL Field Descriptions

 

 

 

Bits

Name

Description

 

 

 

0Ð26

Ñ

Reserved. This bit reads as zero.

 

 

 

27

BC_REJ

Broadcast frame reject.

 

 

If set, frames with DA + 0xFFFF_FFFF_FFFF are rejected unless the PROM bit set. If both

 

 

BC_REJ and PROM = 1, frames with broadcast DA are accepted and RxBD[M] is set.

 

 

 

28

PROM

Promiscuous mode.

 

 

0Promiscuous mode disabled

 

 

1Promiscuous mode enabled. All frames are accepted regardless of address matching.

 

 

 

29

MII_MODE

Selects external interface mode for both transmit and receive blocks.

 

 

0 Selects seven-wire mode (used only for serial 10 Mbps)

 

 

1 Selects MII mode.

 

 

 

30

DRT

Disable receive on transmit.

 

 

0 Receive path operates independently of transmit (use for full duplex or to monitor transmit

 

 

Selects seven-wire mode (used only for serial 10 Mbps)

 

 

1 Disable reception of frames while transmitting (normally used for half-duplex mode)

 

 

 

31

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 TX_CLK when

 

 

LOOP is asserted. DRT must be 0 when asserting LOOP.

 

 

 

6.2.21 Receive Hash Register (R_HASH)

With revision D of the MPC860T silicon, R_HASH[MAX_FRAME_LENGTH], shown in Figure 6-21, is programmable. This field lets the user set the frame length (in bytes) at which the BABR and BABT interrupts and RxBD[LG] should be set. In the B.x revisions of the MPC860T, the value is hard-wired to 1518 bytes.

Bits

0

1

2

3

4

5

6

7

 

8

9

10

11

 

12

13

14

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Field

 

 

 

 

 

 

 

 

Ñ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

 

 

 

 

 

0000_0000_0000_0000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

Read/write

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Addr

 

 

 

 

 

 

 

0xF48

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bits

16

17

18

19

20

21

22

23

 

24

25

26

27

 

28

29

30

31

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Field

 

 

Ñ

 

 

 

 

 

 

MAX_FRAME LENGTH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

 

 

 

 

 

0000_0101_1110_1110

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

Read/write

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Addr

 

 

 

 

 

 

 

0xF4A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 6-21. R_HASH Register

6-20MPC860T (Rev. D) Fast Ethernet Controller Supplement MOTOROLA

PRELIMINARYÑSUBJECTFor ore nformationTO CHANGEOn ThisWITHOUTProduct,NOTICE

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Freescale Semiconductor MPC860T Receive Hash Register Rhash, describes Rcntrl Þelds, Rcntrl Field Descriptions, Bcrej