
MOTOROLA
Chapter 13. QADC64E Legacy Mode Operation
13-71
QADC64E Integration Requirements
13.7.1
Port Digital Input/Output Signals
The 16 port signals on the QADC64E module can be used as analog inputs. Port A signals
can be configured as digital input or digital output signals and Port B signals can be used
as 8-bit digital input signals.
Port A signals are referred to as PQA[7:0] when used as a bidirectional 8-bit digital
input/output port. These eight signals may be used for general-purpose digital input signals
or push-pull digital output signals. Port B signals are referred to as PQB[7:0] when used as
digital input signals.
Port A and B signals 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
Port A signals are configured as inputs or outputs by programming the port data direction
register, DDRQA. The digital input signal states are read from the port data register,
PORTQA, when the port data direction register specifies that the signals are inputs. The
digital data in the port data register is driven onto the port A signals when the corresponding
bit in the port data direction register specifies that the signals are outputs. Refer to
configured as push-pull drivers, external pull-up provisions are not necessary when the
output is used to drive another integrated circuit.
13.7.2
External Trigger Input Signals
The QADC64E uses two external trigger signals (ETRIG[2:1]). Each of the two input
external trigger signals is associated with one of the scan queues, queue 1 or queue 2 The
assignment of ETRIG[2:1] to a queue is made in the QACR0 register by the TRG bit. When
TRG=0, ETRIG[1] triggers queue 1 and ETRIG[2] triggers queue 2. When TRG=1,
ETRIG[1] triggers queue 2 and ETRIG[2] triggers queue 1.
NOTE
The ETRIG[2:1] pins on the MPC561/MPC563 are
multiplexed with the PCS[7:6] pins.
13.7.3
Analog Power Signals
VDDA and VSSA signals supply power to the analog subsystems of the QADC64E module.
Dedicated power is required to isolate the sensitive analog circuitry from the normal levels