MPC564MZP66 Freescale Semiconductor, MPC564MZP66 Datasheet - Page 589

• Manufacturer Part Number: MPC564MZP66
• Description: IC MCU 512K FLASH 66MHZ 388-BGA
• Manufacturer: Freescale Semiconductor
• Series: MPC5xxr

Specifications of MPC564MZP66

• Core Processor: PowerPC
• Core Size: 32-Bit
• Speed: 66MHz
• Connectivity: CAN, EBI/EMI, SCI, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 56
• Program Memory Size: 512KB (512K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 2.5 V ~ 2.7 V
• Data Converters: A/D 32x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 388-BGA
• For Use With: MPC564EVB - KIT EVAL FOR MPC561/562/563/564
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

continuously and queue 2, being lower in priority, never gets executed. The short interval of time between
a queue 1 completion and the subsequent trigger event is not sufficient to allow queue 2 execution to begin.
The software initiated continuous-scan mode is a useful choice with queue 2 for converting channels that
do not need to be synchronized to anything, or for the slow-to-change analog channels. Interrupts are
normally not used with the software initiated continuous-scan mode. Rather, the software reads the latest
conversion result from the result table at any time. Once initiated, software action is not needed to sustain
conversions of channel.
14.4.4.4.2
The QADC64E provides external trigger signals for both queues. When the external trigger software
initiated continuous-scan mode is selected, a transition on the associated external trigger signal initiates
queue execution. The polarity of the external trigger signal is programmable, so that the software can select
a mode which begins queue execution on the rising or falling edge. Each CCW is read and the indicated
conversions are performed until an end-of-queue condition is encountered. When the next external trigger
edge is detected, the queue execution begins again automatically. Software initialization is not needed
between trigger events.
When a pause bit is encountered in external trigger continuous-scan mode, another trigger event is required
for queue execution to continue. Software involvement is not needed to enable queue execution to continue
from the paused state.
Some applications need to synchronize the sampling of analog channels to external events. There are cases
when it is not possible to use software initiation of the queue scan sequence, since interrupt response times
vary.
14.4.4.4.3
The QADC64E provides external gating for queue 1 only. When external gated continuous-scan mode is
selected, the input level on the associated external trigger signal enables and disables queue execution. The
polarity of the external gated signal is fixed so a high level opens the gate and a low level closes the gate.
Once the gate is open, each CCW is read and the indicated conversions are performed until the gate is
closed. When the gate opens again, the queue execution automatically begins again from the beginning of
the queue. Software initialization is not needed between trigger events. If a pause in a CCW is encountered,
the pause flag will not set, and execution continues without pausing.
The purpose of external gated continuous-scan mode is to continuously collect digitized samples while the
gate is open and to have the most recent samples available. It is up to the programmer to ensure that the
queue is large enough so that a maximum gate open time will not reach an end-of-queue. However it is
useful to take advantage of a smaller queue in the manner described in the next paragraph.
In the event that the queue completes before the gate closes, a completion flag will be set and the queue
will roll over to the beginning and continue conversions until the gate closes. If the gate remains open and
the completion flag is not cleared, when the queue completes a second time the trigger overrun flag will
be set and the queue will roll-over again. The queue will continue to execute until the gate closes or the
mode is disabled.
Freescale Semiconductor
External Trigger Continuous-Scan Mode
External Gated Continuous-Scan Mode
MPC561/MPC563 Reference Manual, Rev. 1.2
QADC64E Enhanced Mode Operation
14-47