XR22804 Datasheet, PDF (41/47 Pages) Exar Corporation – Hi-Speed USB to 10/100 Ethernet Bridge with 4 UARTs

XR22804
EDGE_INTR_NEG_EDGE_0 (0x3CB) - Read/Write
Bit
15:0
Default
Description
0xFFFF
E[15:0]
Writing a ’1’ in this register enables an interrupt to be generated on the falling edge of the corresponding bit
position EDGE IO pin(s) configured as an input if the EDGE_INTR_MASK register is enabled for that pin. If the
EDGE_INTR_POS_EDGE register is also enabled, interrupts will be generated on both edges. Writing to an
EDGE pin configured as an output has no effect.
0: IO pin will not generate an interrupt on falling edge
1: IO pin assigned to EDGE function and configured as an input will generate an interrupt on falling edge if cor-
responding EDGE_INTR_MASK bit is set
EDGE_FUNC_SEL_1 (0x3CC) - Read/Write
Bit
31:16
Default
Description
0x0000
E[31:16]
0: IO is assigned to the UART / GPIO function. IO pin controlled using UART registers.
1: IO is assigned to the EDGE function. IO pin controlled using EDGE registers.
EDGE_DIR_1 (0x3CD) - Read/Write
Note that when setting direction of an EDGE IO to output, the EDGE_PULL_UP for that IO pin should also be disabled and
when setting an EDGE IO pin to input, the EDGE_PULL_UP for that IO pin should also be enabled.
Bit
31:16
Default
Description
0x0000
E[31:16]
0: IO pin assigned to EDGE function is configured as an input
1: IO pin assigned to EDGE function is configured as an output.
EDGE_SET_1 (0x3CE) - Write Only
Bit
31:16
Default
Description
0x0000
E[31:16]
0: No effect
1: Set IO pin assigned to EDGE function and configured as an output to a logic ‘1’
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Rev 1B