8 fec transmit fsm register-mbar + 0x31c8, 9 initialization sequence, 1 hardware controlled initialization – Freescale Semiconductor MPC5200B User Manual

Page 499: Fec transmit fsm register—mbar + 0x31c8 -34, Initialization sequence -34, Hardware controlled initialization -34, Fec transmit fsm register -34, Ether_en de-assertion affect on fec -34, Section 14-39, fec transmit fsm register, Table 1-1

Advertising
background image

MPC5200B Users Guide, Rev. 1

14-34

Freescale Semiconductor

Initialization Sequence

14.8.8

FEC Transmit FSM Register—MBAR + 0x31C8

The transmit finite state machine register (XMIT_FSM) controls operation of appending CRC. Typical use is enabled and CRC is appended.

14.9

Initialization Sequence

This section describes which registers are hardware reset, which are reset by the FEC and what locations the user must initialize prior to
enabling the FEC.

14.9.1

Hardware Controlled Initialization

Some registers in the FEC are reset by internal logic. Specifically those registers are control logic that generate interrupts, cause outputs to be
asserted and, in general, configuration control bits.

Other registers are reset when the ETHER_EN bit is not asserted (i.e., cleared). To halt operation ETHER_EN is deasserted by either a hard
reset or by software. By deasserting ETHER_EN configuration control registers such as X_CNTRL and R_CNTRL are not reset, but the entire
data path is reset.

Table 14-40

shows the effect deasserting ETHER_EN has on Ethernet MAC operation and registers.

7

RCTL[0]

0 = Disable fec_enable as a reset to FIFO controllers.

1 = Enable fec_enable as a reset to FIFO controllers.

8:31

---

Reserved

Table 14-39. FEC Transmit FSM Register

msb 0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

R

Reserved

XFS

M

[1

]

XFS

M

[0

]

Reserved

W

RESET:

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31 lsb

R

Reserved

W

RESET:

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Bits

Name

Description

0:5

Reserved

6

XFSM[1]

0 = Do not append CRC.

1 = Append CRC (typical use).

7

XFSM[0]

0 = Disable CRC FSM.

1 = Enable CRC FSM (typical use is enabled).

8:31

---

Reserved

Table 14-40. ETHER_EN De-Assertion Affect on FEC

Register/Machine

Reset Value

XMIT block

Transmission Aborted (bad CRC appended)

RECV block

Receive activity aborted

Tx/Rx FIFO

Reset control logic dependent on reset_cntrl

Table 1-1.

Bits

Name

Description

Advertising