XR21B1420IL28-0A Datasheet, PDF (26/60 Pages) Exar Corporation – Enhanced 1-Ch Full-Speed USB UART

GPIO_STATE (0x010) - Read/Write
Bit
15:10
9:0
Default
Description
0
Reserved
These bits are reserved and should be ‘0.’
0
GPIO State of GPIO[9:0]
Read returns state of all pins, whether GPIO or alternate function, input or output
0: Write clears the respective GPIO output to a ’0’
1: Write sets the respective GPIO output to a ’1’
XR21B1420
GPIO_INT_MASK (0x011) - Read/Write
This register is used to configure whether a change in pin state causes the device to generate a USB interrupt packet. Note
that the GPIO status register will still report the GPIO pin state when read, and if an interrupt packet is formed due to other
interrupt trigger, the interrupt packet will contain the current state of the pin. This register applies to all inputs pins irrespec-
tive of if they are configured as GPIO or alternate functions.
Bit
15:10
9:0
Default
Description
0
0x100
Reserved
These bits are reserved and should be written as ‘0’.
GPIO Interrupt Mask of GPIO[9:0]
0: A change in the input pin's state causes the device to generate an interrupt packet
1: A change in the input pin's state does not cause the device to generate an interrupt packet
CUSTOMIZED_INT (0x012) - Read/Write
This register enables the customized interrupt packet format that will report all GPIO pin status in the interrupt packet.
Bit
15:2
1
0
Default
Description
0
Reserved
These bits are reserved and should be written as ‘0’.
0
Break Interrupt Enable
0: No interrupt is generated when break character is received.
1: Interrupt is generated when break character is received.
0
Enable
0: Use standard interrupt packet. See Table 6.
1: Use customized interrupt packet. See Table 8.
© 2014 Exar Corporation
26 / 60
exar.com/XR21B1420
Rev 1A