Universal Serial Bus
M30240 Group
Rev.1.00 Sep 24, 2003 Page 295 of 360
3.2.2.1 USB Control Register
This register is used to control the operation of the USB function control unit. This register is not af-
fected by a USB reset.
• Transceiver Voltage Converter Current Mode Selection Bit
This bit is used to decrease power consumption. It should be set to “1” when in the suspended state.
This should always be set to “0” when the USB is in normal operation.
• USB Transceiver Voltage Converter Enable Bit
This should be set to “1” when the internal USB DC-DC converter is being used.
• USB Clock Enable Bit
This should be set to “1” to enable the USB clock.
• USB SOF
Port Selection Bit
Set this to “1” when the USB SOF
signals are being used. In such cases, configure the P8
6
pin to the
output mode.
• USB Enable Bit
When this is set to “1” the USB functions are enabled. After the USB is enabled, a minimum delay of
250 ns is needed before performing any other USB register read/write operations.
Figure 3.7 shows the structure of the USB Control register.
0328
16
USB Reserved
0329
16
USB Endpoint 3 IN Control / Status Register EP3ICS
032A
16
USB Endpoint 3 OUT Control / Status Register EP3OCS
032B
16
USB Endpoint 3 IN Maximum Packet Register EP3IMP
032C
16
USB Endpoint 3 OUT Maximum Packet Register EP3OMP
032D
16
USB Endpoint 3 OUT Write Count Register EP3WC
032E
16
USB Reserved
032F
16
USB Reserved
0330
16
USB Reserved
0331
16
USB Endpoint 4 IN Control / Status Register EP4ICS
0332
16
USB Endpoint 4 OUT Control / Status Register EP4OCS
0333
16
USB Endpoint 4 IN Maximum Packet Register EP4IMP
0334
16
USB Endpoint4 OUT Maximum Packet Register EP4OMP
0335
16
USB Endpoint 4 OUT Write Count Register EP4WC
0336
16
USB Reserved
0337
16
USB Reserved
0338
16
USB Endpoint 0 FIFO EP0
0339
16
USB Endpoint 1 FIFO EP1
033A
16
USB Endpoint 2 FIFO EP2
033B
16
USB Endpoint 3 FIFO EP3
033C
16
USB Endpoint 4 FIFO EP4
To Next Page
Loading...
Need help?
General
