Usb hc control head endpoint descriptor register, 0x102 – Freescale Semiconductor MPC5200B User Manual

Page 417

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MPC5200B Users Guide, Rev. 1

12-14

Freescale Semiconductor

Host Control (HC) Operational Registers

12.4.3.3

USB HC Control Head Endpoint Descriptor Register —MBAR + 0x1020

The HC Control Head Endpoint Descriptor register contains the physical address of the first endpoint descriptor of the Control list.

12.4.3.4

USB HC Control Current Endpoint Descriptor Register —MBAR + 0x1024

The HC Control Current Endpoint Descriptor register contains the physical address of the current control list endpoint descriptor.

12.4.3.5

USB HC Bulk Head Endpoint Descriptor Register—MBAR + 0x1028

The HC Head Endpoint Descriptor register contains the physical address of the first bulk list endpoint descriptor.

Table 12-9. USB HC Control Head Endpoint Descriptor Register

msb 0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

R

CHED

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

CHED

Reserved

W

RESET:

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Bits

Name

Description

0:27

CHED

ControlHeadED—HC traverses the control list starting with the HcControlHeadED pointer.
Content is loaded from HCCA during HC initialization.

28:31

Reserved

Table 12-10. USB HC Control Current Endpoint Descriptor Register

msb 0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

R

CCED

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

CCED

Reserved

W

RESET:

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Bits

Name

Description

0:27

CCED

ControlCurrentED—pointer is advanced to next ED after serving the present one. HC
continues processing the list from where it left off in the last frame. When it reaches the control
list end, HC checks the HcCommandStatus ControlListFilled.

If set, CCED copies HcControlHeadED content to HcControlCurrentED and clears bit.

If not set, it does nothing.

HCD is allowed to modify this register only when the ControlListEnable of HcControl is cleared.
When set, HCD only reads the instantaneous value of this register. Initially, this is set to 0 to
indicate the end of the Control List.

28:31

Reserved

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