MMC2107 Datasheet, PDF (407/618 Pages) –

Freescale Semiconductor, Inc.
Queued Analog-to-Digital Converter (QADC)
Signals
18.6.1.2 Port QA Digital Input/Output Pins
Port QA pins are referred to as PQA[4:3, 1:0] when used as a
bidirectional 4-bit digital input/output port. These four pins may be used
for general-purpose digital input signals or digital output signals.
Port QA pins are connected to a digital input synchronizer during reads
and may be used as general-purpose digital inputs when the applied
voltages meet high-voltage input (V_IH) and low-voltage input (V_IL)
requirements.
Each port QA pin is configured as an input or output by programming the
upper half of the port data direction register (DDRQA). The digital input
signal states are read by the software in the upper half of the port data
register when the port data direction register specifies that the pins are
inputs. The digital data in the port data register is driven onto the port QA
pins when the corresponding bit in the port data direction register
specifies output. Since the outputs are configured as output drivers,
external pullup provisions are not necessary when the output is used to
drive another integrated circuit.
18.6.2 Port QB Pin Functions
The four port QB pins can be used as analog inputs or as an 4-bit digital
input-only port.
18.6.2.1 Port QB Analog Input Pins
When used as analog inputs, the four port QB pins are referred to as
AN[3:0]. Since port QB functions as analog and digital input only, the
analog characteristics may be different from those of port QA.
18.6.2.2 Port QB Digital Input Pins
Port QB pins are referred to as PQB[3:0] when used as an 4-bit digital
input only port. In addition to functioning as analog input pins, the port
QB pins are also connected to the input of a synchronizer during reads
and may be used as general-purpose digital inputs when the applied
voltages meet V_IH and V_IL requirements.
MMC2107 – Rev. 2.0
MOTOROLA
Queued Analog-to-Digital Converter (QADC)
For More Information On This Product,
Go to: www.freescale.com
Technical Data
407