Section 13-16, sdma initiator priority 0 register – Freescale Semiconductor MPC5200B User Manual

Page 447

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MPC5200B Users Guide, Rev. 1

13-14

Freescale Semiconductor

BestComm DMA Registers—MBAR+0x1200

13.15.16 SDMA Initiator Priority 0 Register—MBAR + 0x123C

SDMA Initiator Priority 1 Register—MBAR + 0x123D

SDMA Initiator Priority 2 Register—MBAR + 0x123E

SDMA Initiator Priority 3 Register—MBAR + 0x123F

Table 13-16. SDMA Initiator Priority 0 Register

SDMA Initiator Priority 1 Register
SDMA Initiator Priority 2 Register
SDMA Initiator Priority 3 Register

msb 0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

R

IPR0

Hold

Reserved

Prior [2:0]

IPR1

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

IPR2

IPR3

W

RESET:

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Bit

Name

Description

Each of the thirty-two initiators has an associated priority level. Only one register is shown. All bits are set to ‘0 at reset.

0

IPR0 Hold

Hold - Keep current priority of initiator

0 = Allow higher priority initiator to block current initiator

1 = Hold current initiator priority level

This bit can be set or cleared by the programmer at any time. This bit allows the current
initiator to hold priority until the initiator has negated or the task has finished. When this bit
is cleared, an initiator with a higher priority will block the current initiator and force
arbitration. At system reset, this bit is cleared.

1:4

Reserved

5:7

Prior[2:0]

InitPrior[2:0] - Initiator/Task priority level.

These bits can be set by the programmer at any time. These bits control the priority of the
requestor/task which will be serviced next depending on the setting of the T/I bit in the
PtdControl register.

The highest priority is level 7. The lower priority is level 0.. If more than one initiator/task
contains the same priority then the order of the task within the Task table (task 7 highest
to task 0 lowest) will set the priority.

8:15

IPR1

Initiator Priority register for initiator 1 (or Task1 if PtdControl[16]=1).

Same bit layout as IPR0

16:23

IPR2

Initiator Priority register for initiator 2.(or Task2 if PtdControl[16]=1)

Same bit layout as IPR0

24:31

IPR3

Initiator Priority register for initiator 3.(or Task3 if PtdControl[16]=1)

Same bit layout as IPR0

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