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enCoRe™ V CY7C643xx, enCoRe™ V LV CY7C604xx TRM, Document No. 001-32519 Rev *H
215
1,30h
21.4.4
USB_CR1
USB Control Register 1
This register is used to configure the internal regulator and the oscillator tuning capability.
This register is only used by the CY8C20XX6A/AS/LCY7C64215 enCoRe V devices. In the table, note that reserved bits are
grayed table cells and are not described in the bit description section. Reserved bits must always be written with a value of ‘0’.
For additional information, refer to the
Register Definitions on page 147
in the Full-Speed USB chapter.
2
BusActivity
Monitors activity on USB bus. This bit is only set by the hardware. Writing a ‘0’ clears this bit. Writing
a ‘1’ preserves its present state.
0
No activity.
1
Non-idle activity (D+ = Low) was detected since the last time the bit was cleared.
1
EnableLock
Controls the automatic tuning of the internal oscillator. Hardware locks the internal oscillator based on
the frequency of incoming USB data when this bit is set. Normally, this is set when the device is used
in a USB application.
0
Locking disabled.
1
Locking enabled.
0
RegEnable
Configures USB regulator for appropriate power supply range.
0
Pass-through mode. Use for Vdd = 3.3-V range.
1
Regulating mode. Use for Vdd = 5-V range.
Individual Register Names and Addresses:
1,30h
USB_CR1 : 1,30h
7
6
5
4
3
2
1
0
Access : POR
RC : 0
RW : 0
RW : 0
Bit Name
BusActivity
EnableLock
RegEnable
Bit
Name
Description