XR17D158_05 Datasheet, PDF (24/73 Pages) Exar Corporation – UNIVERSAL (3.3V AND 5V) PCI BUS OCTAL UART

XR17D158
UNIVERSAL (3.3V AND 5V) PCI BUS OCTAL UART
FIGURE 8. MULTIPURPOSE INPUT/OUTPUT INTERNAL CIRCUIT
MPIOINT [7:0]
INT
AND
Rising Edge
Detection
AND
xr
REV. 1.2.2
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 0 (default) disables the pin’s interrupt and logic 1 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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