XR21B1420IL28-0A Datasheet, PDF (25/60 Pages) Exar Corporation – Enhanced 1-Ch Full-Speed USB UART

XR21B1420
GPIO_DIRECTION (0x00D) - Read/Write
This register controls the direction of pins that are configured as GPIO. Pins that are configured for alternate functions via
the GPIO_MODE register are not controlled by this register.
Bit
15:10
9:0
Default
0
Reserved
These bits are reserved and should be ‘0.’
0
GPIO Direction of GPIO[9:0]
0: GPIOx is an input.
1: GPIOx is an output.
Description
GPIO_SET (0x00E) - Write-Only
This register controls pins configured as GPIO outputs. Pins configured for alternate functions via the GPIO_MODE register
are not controlled by this register. Writing a ’1’ to a bit position in this register sets the corresponding GPIO output high. Writ-
ing a ’0’ to a bit has no effect. For GPIO pins configured as inputs via the GPIO_DIRECTION register, this register has no
effect.
Bit
15:10
9:0
Default
0
Reserved
These bits are reserved and should be ‘0.’
0
GPIO Set of GPIO[9:0]
0: No effect on GPIOx pin.
1: GPIOx output is set to a ’1.’
Description
GPIO_CLEAR (0x00F) - Write-Only
This register controls pins configured as GPIO outputs. Pins configured for alternate functions via the GPIO_MODE register
are not controlled by this register. Writing a ’1’ to a bit position in this register clears the corresponding GPIO output low.
Writing a ’0’ to a bit has no effect. For GPIO pins configured as inputs via the GPIO_DIRECTION register, this register has
no effect.
Bit
15:10
9:0
Default
0
Reserved
These bits are reserved and should be ‘0.’
0
GPIO Set of GPIO[9:0]
0: No effect on GPIOx pin.
1: GPIOx output is cleared to a ’0’.
Description
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Rev 1A