Intel PXA27 Series Design Manual page 268

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Intel PXA27x Processor and Intel
D.24 General-Purpose I/O Unit
The GPIO controllers in the PXA27x processor and PXA25x processor are similar with these
exceptions.
•
Features added to the PXA27x processor GPIO controller:
— There are now 119 GPIOs in discrete packages and 121 GPIOs in Intel® PXA27x
Processor Family, whereas in the PXA25x processor, there are 81 GPIOs.
— Some alternate functions of the PXA27x processor have signals that are bidirectional.
When these alternate configurations are selected, the signal becomes bidirectional and the
value of GPDR for that GPIO is ignored.
— The power manager is able to override the configuration of GPIO<10:2> for GPIO reset
(when PCFR[GPR_EN] is set).
•
Changes to the registers within the PXA25x processor interrupt controller were required to
support the new features of the PXA27x processor GPIO controller:
— Extra registers were added to the PXA27x processor to support the extra GPIOS. Where
there were three registers for a function in the PXA25x processor (for example, GPDR0,
GPDR1, and GPDR2). There are now four sets of registers in the PXA27x processor (for
example, GPDR0, GPDR1, GPDR2, and GPDR3).
— The mapping of the alternate functions to the GAFR registers has changed from that of the
PXA25x processor.
D.25 Interrupt Controller
The interrupt controllers in the PXA27x processor and PXA25x processor are similar with these
exceptions.
•
Features added to the PXA27x processor interrupt controller:
— Priority mechanism to indicate highest priority interrupt.
— Accessibility to interrupt control/status registers using the coprocessor interface.
•
Changes to the registers within the PXA25x processor interrupt controller were required to
support the new features of the PXA27x processor interrupt controller:
— All register that existed in the PXA25x processor have additional bits to support the 10
additional interrupt signals in the PXA27x processor controller.
— IPRx registers have been added to the PXA27x processor interrupt controller to support
the new interrupt priority scheme.
Note: The only register that remains unchanged is the ICCR register.
D-14
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PXA25x Processor Differences
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Intel PXA27x Processor Family Design Guide