nRF24LE1 Nordic VLSI, nRF24LE1 Datasheet - Page 129

• Manufacturer Part Number: nRF24LE1
• Manufacturer: Nordic VLSI

nRF24LE1 Preliminary Product Specification
17.2.2
The PortCrossbar sets up connections between the IO pins and the peripheral block of the device.
17.2.2.1
The PortCrossbar modifies connections dynamically based on run-time variations in system needs of the
peripheral blocks (SPI, 2 wire etc) of the device. This feature is necessary because the number of available
pins is small compared to the combined IO needs of all the peripheral blocks. Consequently, on the smaller
package options there may be conflicting pin assignments. These are resolved through a set of priorities
assigned to each peripheral block. The pin out tables for each package option can be seen in
page
17.2.2.2
Each digital peripheral block that needs an IO is represented in the pin out tables with the interface names
of the block and the direction enforced on each pin. The priority of the blocks relative to potentially conflict-
ing blocks is also shown. If the block is enabled, and no higher priority block is enabled, all the IO needs
are granted. The PortCrossbar never grants partial fulfilment of a digital IO request even if a conflict exists
only for some of the pins. A requesting digital device gets all or none of its IO needs granted.
17.2.2.3
A dynamic request for analog IO is similar to that of a digital IO. However, for analog blocks only the inter-
face signals actually used as inputs to the analog blocks, configured by ADCCON1.chsel and
ADCCON1.refsel, are connected to a device pin. This is different from the digital peripheral blocks where
all the IO of a block are reserved once the block is enabled.
The two analog blocks, ADC and analog comparator, share a column in the pin out tables. This is done
because the comparator uses the ADC configuration registers for selecting the source pins for its signal
and voltage reference inputs. Please refer to
details.
The IO needs of the XOSC32K are also run-time programmable. Depending on configuration, this block
may request either analog or digital IO. See
If analog functionality is enabled for a pin, this is done without modifying or disabling the pins digital config-
uration. If particular digital input and/or output configuration are necessary for an analog pin to function cor-
rectly, this configuration must be enabled in registers PxCON and PxDIR separately, before enabling the
analog block.
17.2.2.4
If no peripheral blocks request IO, a default pinout as listed in the default column in the pin out maps are
enabled. This means that all device pins are used for MCU GPIO. After reset, all IOs are configured to be
digital inputs. The features, direction and IO data on the pins are in this case controlled by registers PnCON ,
PnDIR and Pn .
Revision 1.1
131,
Note: The implementation does not prevent simultaneous digital and analog use of a pin. If a pin is
Table 75. on page 132
to be used for analog input, digital I/O buffers and digital peripheral blocks connected to the
same pin should normally be disabled. Conflicts between analog blocks are resolved through
priority.
PortCrossbar functionality
Dynamic allocation of pins
Dynamic pin allocation for digital blocks
Dynamic pin allocation for analog blocks
Default pin allocation
and
Table 76. on page
section 13.3.4 on page 117
chapter 21 on page 160
129 of 191
135.
and
for further details.
chapter 22 on page 166
Table 74. on
for more