XR21B1424_17 Datasheet, PDF (40/64 Pages) Exar Corporation – Enhanced 4-Ch Full-Speed USB UART

Bit
7
6
5:4
3
2
1
0
Default
Description
0
RXT
0: When USE_SUSPEND is ’1,’ output will be actively driven
1: When USE_SUSPEND is ’1,’ output will be open drain
0
TXT
0: When USE_SUSPEND is ’1,’ output will be actively driven
1: When USE_SUSPEND is ’1,’ output will be open drain
0
Reserved
These bits are reserved and should be written as ‘0’.
0
RS485
0: When USE_SUSPEND is ’1,’ output will be actively driven
1: When USE_SUSPEND is ’1,’ output will be open drain
0
CTS
0: When USE_SUSPEND is ’1,’ output will be actively driven
1: When USE_SUSPEND is ’1,’ output will be open drain
0
RTS
0: When USE_SUSPEND is ’1,’ output will be actively driven
1: When USE_SUSPEND is ’1,’ output will be open drain
0
CLK
0: When USE_SUSPEND is ’1,’ output will be actively driven
1: When USE_SUSPEND is ’1,’ output will be open drain
XR21B1424
REVISION_ID (0x260) - Read-Only
Bit
15:0
Default
0
Revision ID
Description
USB_STATUS (0x262) - Read-Write (except as noted)
Bit
15:14
13
12:10
Default
Description
0
Reserved
These bits are reserved and should be written as ‘0’.
0
STATE1 - Read only
Returns the current state of the USB_STAT2 pin.
0
SEL1
000: USB_STAT2 asserted high when in suspended state or when USB bus reset is asserted
001: USB_STAT2 asserted high when in suspended state
010: For low power device (<= 100 mA) USB_STAT2 asserted high when in suspended state. For high power device (101-500
mA) asserted high when in suspended state or when not yet configured.
011: USB_STAT2 asserted high when USB bus reset is asserted
100: USB_STAT2 asserted high when in suspended state or when USB bus reset is asserted
101: USB_STAT2 asserted low when in suspended state
110: For low power device (<= 100 mA) USB_STAT2 asserted low when in suspended state. For high power device (101-500
mA) asserted low when in suspended state or when not yet configured.
111: USB_STAT2 asserted low when USB bus reset is asserted
40 / 64
exar.com/XR21B1424
Rev 1C