Universal Serial Bus
M30240 Group
Rev.1.00 Sep 24, 2003 Page 297 of 360
3.2.2.3 USB Address Register
This register holds the seven-bit USB address that is assigned from the host CPU. The USB function
control unit uses the value of this register to decode USB token packet addresses. Before the device
is configured at reset, the value is 00
16
.
Figure 3.9 shows the structure of the USB address register.
Figure 3.9: USB Function Address Register (USBA)
3.2.2.4 USB Power Management Register
This register is used to manage the electrical power of the USB function control unit.
• USB Suspend Detection Flag
When the USB FCU does not detect any bus activity on D+/D- for at least 3ms, the USB Suspend De-
tect Flag is set to “1” and a USB suspend interrupt request is generated. When resume detection from
the host CPU is detected, this bit is cleared to”0.” When the Remote WakeUp (timer, etc.) is used to
recover from the suspend mode, this bit is automatically cleared at the same time that the USB remote
wake up bit is cleared.
• USB Resume Detection Flag
When the USB FCU is in the suspend state and detects activity on D+/D- from the host, this flag be-
comes “1” and a USB resume interrupt request is generated. This bit is automatically cleared at the
same time that the USB resume interrupt status flag (INTST14) is cleared.
• USB Remote Wake Up Bit
Set the remote Wake Up Bit to “1” when it (timer, reset, etc.) is used to return from the suspend mode.
While the bit is “1”, the USB function control unit transmits a resume signal to the host CPU and notifies
the return from the suspended status. After holding this bit for 10ms to 15ms at”1”, clear it to “0.”
Figure 3.10 shows the structure of the USB Power Control Register
Figure 3.10: USB Power Management Register (USBPM)
Bit Symbol Bit Name Function R W
FUNAD-6
Reserved
Function Address
7-bit programmable
Function Address
Must always be set to "0"
O O
O O
O
Symbol
USBA
Address
0300
16
When reset
00
16
USB Function Address Register
b7 b5b6 b4 b3 b2 b1 b0
Bit Symbol Bit Name Function R W
SUSPEND
Reserved
USB Suspend Detection Flag
0: Signal not detected
1: Signal detected
Must always be set to "0"
O O
O O
O O O O O
Symbol
USBPM
Address
0301
16
When reset
00
16
USB Power Management Register
b7 b5b6 b4 b3 b2 b1 b0
RESUME
USB Resume Detection Flag
0: Signal not detected
1: Signal detected
O O
WAKE UP USB Remote Wake up Bit
0: End remote resume signaling
1: Remote resume signaling (Note 2)
O O
Note 1
Note 1
Note 1: Write "0" only or Read
Note 2: If SUSPEND = "1"
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