4 tx enables pciter(rw)-mbar + 0x380c – Freescale Semiconductor MPC5200B User Manual

Page 323

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MPC5200B Users Guide, Rev. 1

10-26

Freescale Semiconductor

Registers

10.3.3.1.4

Tx Enables PCITER(RW)—MBAR + 0x380C

msb 0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

R

RC

RF

Rsvd

CM

BE

Reserved

ME

Reserved

FEE

SE

RE

TAE

IAE

NE

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

Reset

Controller

(RC)

User writes this bit high to put Transmit Controller in a reset state. Other register bits are not
affected. This Reset is intended for recovery from an error condition or to reload the Start
Address when Continuous mode is selected. This Reset bit does not prohibit register
access but it must be negated in order to initiate a Restart sequence (i.e. writing the
Packet_Size register). If it is used to reload a Start Address then the Start_Add register must
be written prior to asserting this Reset bit.

1

Reset

FIFO

(RF)

The FIFO will be reset and flushed of any existing data when set high. The Reset Controller
bit and the Reset FIFO bit operate independently but clearly both must be low for normal
operation.

2

Reserved

Unused bit. Software should write a zero to this bit.

3

Continuous

mode

(CM)

User writes this bit high to activate Continuous mode. In Continuous mode the Start_Add
value is ignored at each packet restart and the PCI address is auto-incremented from one
packet to the next. Also, the Packets_Done status byte will become active, indicating how
many packets have been transmitted since the last Reset Controller condition. If the
Continuous bit is low, software is responsible for updating the Start_Add value at each
packet Restart.

4

Bus error

Enable

(BE)

User writes this bit high to enable Bus Error indications.

Section 10.3.3.1.9, Tx Status

PCITSR(RWC) —MBAR + 0x381C

for Bus Error descriptions. Normally this bit will be low

(negated) since illegal Slave bus accesses are not destructive to register contents (although
it may indicate broken software). This bit does not affect interrupt generation.

5:6

Reserved

Unused. Software should write zero to these bits.

7

Master
Enable

(ME)

This is the Transmit Controller master enable signal. User must write it high to enable
operation. It can be toggled low to permit out-of-order register updates prior to generating
a Restart sequence (in which case transmission will begin when Master Enable is written
back high), but it should not be used as such in Continuous mode because it has the side
effect of resetting the Packets_Done status counter.

8:9

Reserved

Unused. Software should write zero to these bits.

10

FIFO Error

Enable

(FEE)

User writes this bit high to enable CPU Interrupt generation in the case of FIFO error
termination of a packet transmission. It may be desirable to mask CPU interrupts in the case
that Multi-Channel DMA is controlling operation, but in such a case software should poll the
status bits to prevent a possible lock-up condition.

11

System error

Enable

(SE)

User writes this bit high to enable CPU Interrupt generation in the case of system error
termination of a packet transmission. It may be desirable to mask CPU interrupts in the case
that Multi-Channel DMA is controlling operation, but in such a case someone should be
polling the status bits to prevent a possible lock-up condition.

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