CC2430 Datasheet, PDF (79/212 Pages) Texas Instruments – A True System-on-Chip solution for 2.4 GHz IEEE 802.15.4 / ZigBee-TM

CC2430
Peripherals : I/O ports
nibble have their individual interrupt enables.
For the P2_0 – P2_4 inputs there is a common
interrupt enable.
When an interrupt condition occurs on one of
the general purpose I/O pins, the
corresponding interrupt status flag in the P0-
P2 interrupt flag registers, P0IFG , P1IFG or
P2IFG will be set to 1. The interrupt status flag
is set regardless of whether the pin has its
interrupt enable set. When an interrupt is
serviced the interrupt status flag is cleared by
writing a 0 to that flag, and this flag must be
cleared prior to clearing the CPU port interrupt
flag (PxIF).
The I/O SFR registers used for interrupts are
described in section 13.4.9 on page 82. The
registers are summarized below:
• P1IEN : P1 interrupt enables
• PICTL : P0/P2 interrupt enables and P0-2
edge configuration
• P0IFG : P0 interrupt flags
• P1IFG : P1 interrupt flags
• P2IFG : P2 interrupt flags
13.4.5 General Purpose I/O DMA
When used as general purpose I/O pins, the
P0 and P1 ports are each associated with one
DMA trigger. These DMA triggers are IOC_0
for P0 and IOC_1 for P1 as shown in Table 41
on page 94.
The IOC_0 or IOC_1 DMA trigger is activated
when an input transition occurs on one of the
P0 or P1 pins respectively. Note that input
transitions on pins configured as general
purpose I/O inputs only will produce the DMA
trigger.
Note that port registers P0 and P1 are mapped
to XDATA memory space (see Table 24 on
page 35). Therefore these registers are
reachable for DMA transfers. Port register P2
is not reachable for DMA transfers.
13.4.6 Peripheral I/O
This section describes how the digital I/O pins
are configured as peripheral I/Os. For each
peripheral unit that can interface with an
external system through the digital input/output
pins, a description of how peripheral I/Os are
configured is given in the following sub-
sections.
In general, setting the appropriate PxSEL bits
to 1 is required to select peripheral I/O function
on a digital I/O pin.
Note that peripheral units have two alternative
locations for their I/O pins, refer to Table 40.
Also note that as a general rule only two
peripherials can be used per IO Port at a time.
Priority can be set between these if conflicting
settings regarding IO mapping is present.
Priority among unlisted peripherial units is
undefined and should not be used
(P2SEL.PRIxP1 and P2DIR.PRIP0 bits). All
combinations not causing conlicts can be
combined.
CC2430 Data Sheet (rev. 2.1) SWRS036F
Page 79 of 211