XR22804 Datasheet, PDF (42/47 Pages) Exar Corporation – Hi-Speed USB to 10/100 Ethernet Bridge with 4 UARTs

EDGE_CLEAR_1 (0x3CF) - Write Only
Bit
31:16
Default
Description
0x0000
E[31:16]
0: No effect
1: Clear IO pin assigned to EDGE function and configured as an output to a logic ‘0’
XR22804
EDGE_STATE_1 (0x3D0) - Read/Write
Bit
31:16
Default
Description
0x0000
E[31:16]
Writing in this register sets or clears the EDGE IO pin(s) configured as an output. Writing to an EDGE pin con-
figured as an input has no effect. Reading this register returns the state of each IO pin configured as an EDGE
pin irrespective of whether it is configured as an input or output. Note that output transitions across multiple IO
pins may be slightly staggered. Refer to EDGE section on page 17.
0: Write clears the corresponding bit to a ‘0’. Read returns the current state.
1: Write sets the corresponding bit to a ‘1.’ Read returns the current state.
EDGE_TRI_STATE_1 (0x3D1) - Read/Write
Bit
31:16
Default
Description
0x0000
E[31:16]
0: IO pin assigned to EDGE function and configured as an output is actively driven
1: IO pin assigned to EDGE function and configured as an output is tri-stated
EDGE_OPEN_DRAIN_1 (0x3D2) - Read/Write
Bit
31:16
Default
Description
0x0000 E[31:16]
Note that XR22804 open drain outputs have a weak internal pull-up.
0: IO pin assigned to EDGE function and configured as an output is a push-pull output
1: IO pin assigned to EDGE function and configured as an output is an open drain output
EDGE_PULL_UP_1 (0x3D3) - Read/Write
Bit
31:16
Default
Description
0xFFFF
E[31:16]
0: Disable internal pull-up resistor on IO pin assigned to EDGE function and configured as an input
1: Enable internal pull-up resistor on IO pin assigned to EDGE function and configured as an input
© 2015 Exar Corporation
42 / 47
exar.com/XR22804
Rev 1B