USB Device Controller

12.6.2UDC Control Function Register (UDCCFR)

The UDC Control Function register (UDCCFR) contains 1 mode bit and 1 enable bit that lets software delay sending back an ACK response to SET_CONFIG or SET_INTERFACE commands from the host. The remaining bits are reserved.

Table 12-13. UDC Control Function Register

 

 

 

0x 4060_0008

 

 

UDCCFR

 

 

USB Device Controller

 

 

 

Bit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

32

31 30 29 28

27 26 25 24

23 22 21 20

19 18 17 16

15 14 13

12

11 10

9

 

8

 

7

6

5

4

3

 

2

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reserved

 

 

 

 

 

AREN

 

MB1

 

 

 

ACM

MB1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

X

X X X

X

X X X X

X

X X X

X X X X

X X X

X X X X

X 1 1

1

1

1

 

1

1

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bits

 

Name

 

 

 

Description

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

31:8

 

Reserved – Read as unknown and must be written as zero.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ACK RESPONSE ENABLE (read/write 1 to set)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

 

AREN

0 = Send NAK response to SET_CONFIGURATION and SET_INTERFACE

 

 

 

 

 

 

commands

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 = Send ACK response to SET_CONFIGURATION and SET_INTERFACE

 

 

 

 

 

 

 

 

 

commands

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MB1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6:2

 

MB1

This bit must be set to 1.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0 =

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 = Must be configured to 1.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ACK CONTROL MODE (read/write 1 to set)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

ACM

0 = Send ACK response to SET_CONFIGURATION and SET_INTERFACE

 

 

 

 

 

 

commands with no user intervention (B-step default)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 = Send NAK response to SET_CONFIGURATION and SET_INTERFACE

 

 

 

 

 

 

 

 

 

commands until UDCCFR[AREN] = 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MB1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

MB1

This bit must be set to 1.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0 =

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 = Must be configured to 1.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12.6.2.1ACK Control Mode

The ACK control mode (ACM) bit enables user control of the ACK response to the status IN requests of SET_CONFIGURATION and SET_INTERFACE commands. When ACM is set to 0, the UDC automatically responds to the STATUS IN request following a SET_CONFIGURATION and SET_INTERFACE with an ACK. When ACM is set to 1, the UDC responds to the STATUS IN request following a SET_CONFIGURATION and SET_INTERFACE command with a NAK until AREN is set to 1. When the user sets AREN to 1, the UDC responds with an ACK to the next STATUS IN request.

12.6.2.2ACK Response Enable

When ACM = 1, the ACK response enable (AREN) bit enables user control of the ACK response to the status IN requests of SET_CONFIGURATION and SET_INTERFACE commands. When ACM is set to 1, the UDC responds to the STATUS IN request following a

12-24

Intel® PXA255 Processor Developer’s Manual

Page 426
Image 426
Intel PXA255 manual UDC Control Function Register Udccfr, ACK Control Mode, ACK Response Enable