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M451
May. 4, 2018
Page
798
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1006
Rev.2.08
M4
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USB Bus Status and Attribution Register (USBD_ATTR)
Register
Offset
R/W
Description
Reset Value
USBD_ATTR
0x010 R/W
USB Device Bus Status and Attribution Register
0x0000_0040
31
30
29
28
27
26
25
24
Reserved
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
Reserved
BYTEM
PWRDN
DPPUEN
7
6
5
4
3
2
1
0
USBEN
Reserved
RWAKEUP
PHYEN
TOUT
RESUME
SUSPEND
USBRST
Bits
Description
[31:11]
Reserved
Reserved.
[10]
BYTEM
CPU Access USB SRAM Size Mode Selection
0 = Word mode: The size of the transfer from CPU to USB SRAM can be Word only.
1 = Byte mode: The size of the transfer from CPU to USB SRAM can be Byte only.
[9]
PWRDN
Power-down PHY Transceiver, Low Active (M45xD/M45xC Only)
0 = Power-down related circuits of PHY transceiver.
1 = Turn-on related circuits of PHY transceiver.
[8]
DPPUEN
Pull-up Resistor on USB_DP Enable Bit
0 = Pull-up resistor in USB_D+ bus Disabled.
1 = Pull-up resistor in USB_D+ bus Active.
[7]
USBEN
USB Controller Enable Bit
0 = USB Controller Disabled.
1 = USB Controller Enabled.
[6]
Reserved
Reserved.
[5]
RWAKEUP
Remote Wake-up
0 = Release the USB bus from K state.
1 = Force USB bus to K (USB_D+ low and USB_D- high) state, used for remote wake-
up.
[4]
PHYEN
PHY Transceiver Function Enable Bit
0 = PHY transceiver function Disabled.
1 = PHY transceiver function Enabled.
[3]
TOUT
Time-out Status
0 = No time-out.
1 = No Bus response more than 18 bits time.
Note:
This bit is read only.
[2]
RESUME
Resume Status