XR21B1411IL-0A-EB Datasheet, PDF (19/30 Pages) Exar Corporation – ENHANCED 1-CH FULL-SPEED USB UART

REV. 1.2.0
3.1.1.17
XR21B1411
ENHANCED 1-CH FULL-SPEED USB UART
GPIO_STATUS Register Description (Read Only)
This register reports the current state of each of the GPIO pins.
3.1.1.18 GPIO_INT_MASK Register Description (Read / Write)
Dictates whether a change in GPIO pin state causes the device to generate a USB interrupt packet. In either
case, the GPIO status register will still report the pin's 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.
GPIO_INT_MASK[5:0]: GPI0[5:0]
 Logic 0 = A change in the pin's state causes the device to generate an interrupt packet.
 Logic 1 = A change in the pin's state does not cause the device to generate an interrupt packet.
GPIO_INT_MASK[11:6]: Reserved
 These bits are reserved and should remain ’0’.
3.1.1.19 CUSTOMIZED_INT Register Description (Read / Write)
Enables the customized interrupt packet format to report all GPIO status in the interrupt packet.
CUSTOMIZED_INT[0]: Enable
 Logic 0 = Use standard interrupt packet. See Table 9
 Logic 1 = Use customized interrupt packet. See Table 10
CUSTOMIZED_INT[11:1]: Reserved
 These bits are reserved and should remain ’0’.
TABLE 8: INTERRUPT PACKET FORMAT
OFFSET
FIELD
SIZE
(BYTES)
VALUE
DESCRIPTION
0 bmRequestType 1
8’b10100001
D7 = Device-to-host direction
D6:5 = Class Type
D4-0: = Interface Recipient
1
bNotification
1
8’h20
Defined encoding for SERIAL_STATE
2
wValue
2
16’h0000
4
wIndex
2
16’h0000 D15-8 = Reserved (0)
D7-0 = Interface number, 8’h00 for the CDC Com-
mand Interface
6
wLength
2
16’h0002 2 bytes of transferred data
8
Data
2
Standard D15-7 = Reserved (0)
int_status _{D6 = bOverRun}
(See Table 9 or _{D5 = bParity}
Table 10) _{D4 = bFraming}
D3 = bRingSignal (RI)
D2 = bBreak
D1 = bTxCarrier (DSR)
D0 = bRxCarrier (CD)
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