Intel IXC1100, IXP42X - page 388

Intel® IXP42X product line and IXC1100 control plane processors—General Purpose Input/
Output (GPIO)
Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
388 Order Number: 252480-006US
• GPIT1R represents GPIO 0 through GPIO 7
• GPIT2R represents GPIO 8 through GPIO 15
• General-Purpose Interrupt Type Register 1 bits 0 through 2 represent GPIO0
• General-Purpose Interrupt Type Register 1 bits 3 through 5 represent GPIO2, …
• General-Purpose Interrupt Type Register 1 bits 21 through 23 represent GPIO7
• General-Purpose Interrupt Type Register 2 bits 0 through 2 represent GPIO8
• General-Purpose Interrupt Type Register 2 bits 3 through 5 represent GPIO9, …
• General-Purpose Interrupt Type Register 2 bits 21 through 23 represent GPIO15.
The possible settings for each of the 3-bit registers are shown in Table145.
The interrupt detection logic uses a pulse width of five 66-MHz clock cycles before an
interrupt will occur when a GPIO input is configured as an active high or active low
interrupt type. The length of four 66-MHz clocks was chosen to discriminate against
small pulses and ensures that glitches are not detected in the active high and active
low interrupts when configured in these two interrupt modes.
Table 145. GPIO Interrupt Selections
Register
Name GPIO Register Bit Definition Interrupt Description Interrupt
Type
GPIT2R GPIO15 Bit 23 Bit 22 Bit 21 Not used.
GPIO14 Bit 20 Bit 19 Bit 18 Not used.
GPIO13 Bit 17 Bit 16 Bit 15 Not used.
GPIO12 Bit 14 Bit 13 Bit 12 Reset to Active High
GPIO11 Bit 11 Bit 10 Bit 9 Reset to Active High
GPIO10 Bit 8 Bit 7 Bit 6 Reset to Active High
GPIO9 Bit 5 Bit 4 Bit 3 Reset to Active High
GPIO8 Bit 2 Bit 1 Bit 0 Reset to Active High
GPIT1R GPIO7 Bit 23 Bit 22 Bit 21 Reset to Active High
GPIO6 Bit 20 Bit 19 Bit 18 Reset to Active High
GPIO5 Bit 17 Bit 16 Bit 15 Reset to Active High
GPIO4 Bit 14 Bit 13 Bit 12 Reset to Active High
GPIO3 Bit 11 Bit 10 Bit 9 Reset to Active High
GPIO2 Bit 8 Bit 7 Bit 6 Reset to Active High
GPIO1 Bit 5 Bit 4 Bit 3 Reset to Active High
GPIO0 Bit 2 Bit 1 Bit 0 Reset to Active High
000
Interrupt detected after GPIO is logic 1 for five
66-MHz clocks Active High
001
Interrupt detected after GPIO is logic 0 for five
66-MHz clocks Active Low
010
Interrupt detected after GPIO goes from an
logic 0 to logic 1 Rising Edge
011
Interrupt detected after GPIO goes from an
logic 1 to logic 0 Falling Edge
1XX
Interrupt detected after GPIO goes from an
logic 1 to logic 0 or GPIO goes from logic 0 to
logic 1 Transitional