XR17V254 Datasheet, PDF (24/70 Pages) Exar Corporation – 66MHZ PCI BUS QUAD UART WITH POWER MANAGEMENT SUPPORT

XR17V254
66MHZ PCI BUS QUAD UART WITH POWER MANAGEMENT SUPPORT
FIGURE 9. MULTIPURPOSE INPUT/OUTPUT INTERNAL CIRCUIT
MPIOINT [7:0]
INT
AND
Rising Edge
Detection
AND
REV. 1.0.0
1
MPIOLVL [7:0]
Read Input Level
0
MPIO
Pin [7:0]
MPIOINV [7:0]
(Input Inversion Enable =1)
MPIOLVL [7:0]
(Output Level)
MPIO3T [7:0]
(3-state Enable =1)
OR
MPIOSEL [7:0]
(Select Input=1, Output=0 )
MPIOCKT
MPIOINT [7:0] (default 0x00)
Enable multipurpose input pin interrupt. If the pin is selected by MPIOSEL as input then bit [0] enables input
pin 0 for interrupt, and bit [7] enables input pin 7. No interrupt is enable if the pin is selected to be an output.
The interrupt is edge sensing and determined by MPIOINV and MPIOLVL registers. The MPIO interrupt clears
after a read to register MPIOLVL. The combination of MPIOLVL and MPIOINV determines the interrupt being
active LOW or active high, it’s level trigger. Logic LOW (default) disables the pin’s interrupt and logic HIGH
enables it.
MPIOINT Register
Multipurpose Input/Output Interrupt Enable
Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
MPIO7 MPIO6 MPIO5 MPIO4 MPIO3 MPIO2 MPIO1 MPIO0
MPIOLVL [7:0] (default 0x00)
Output pin level control and input level status. The status of the input pin(s) is read on this register and output
pins are controlled on this register. A logic 0 (default) sets the output to LOW and a logic 1 sets the output pin
to HIGH. The MPIO interrupt will clear upon reading this register.
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