MPC564EVB Freescale Semiconductor, MPC564EVB Datasheet - Page 591

• Manufacturer Part Number: MPC564EVB
• Description: KIT EVAL FOR MPC561/562/563/564
• Manufacturer: Freescale Semiconductor
• Type: Microcontrollerr

Specifications of MPC564EVB

• Contents: Module Board, Installation Guide, Power Supply, Cable, Software and more
• Processor To Be Evaluated: MPC56x
• Data Bus Width: 32 bit
• Interface Type: RS-232, Ethernet
• For Use With/related Products: MPC561, 562, 563, 564
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

The MCU system clock frequency (IMB3 system clock – f
QCLK is generated by a software selectable prescaler that divides f
conversion time to be maximized across f
waveform by setting the PRESCALER field in the QACR0 register.
When the value of PRESCALER > 0 the resulting frequency of QCLK is calculated using the following
formula:
The QADC64E requires that f
field is set to Zero, the resulting QCLK frequency is calculated to be:
Freescale Semiconductor
Prescaler Rate Selection
(from Control Register 0)
System Clock (F
Input Sample Time
(From CCW)
QUEUE 1 & 2 Timer
Mode Rate Selection
f
f
QCLK
QCLK
A change in the prescaler value while a conversion is in progress is likely to
corrupt the result from any conversion in progress. Therefore, any prescaler
write operation should be done only when both queues are in the disabled
modes.
= f
= f
SYSCLK
SYSCLK
SYS
)
Figure 14-23. QADC64E Clock Subsystem Functions
/ (PRESCALER + 1)
/ 2
SYSCLK
MPC561/MPC563 Reference Manual, Rev. 1.2
8
be at least twice f
SYSCLK
2 7
WARNING
2 8
. The software establishes the frequency of QCLK
2 9
2 10
Periodic / interval
Binary Counter
A/D Converter
State Machine
Timer Select
QCLK
2 11
2 12
SYSCLK
2 13
. Therefore if the value in the PRESCALER
2 14
( F
2 15
) is the basis of the QADC64E timing.
SYS
SYSCLK
2 16 2 17
QADC Clock
/ ÷2 to F
QADC CLOCK BLOCK
QADC64E Enhanced Mode Operation
thus allowing the A/D
Generate
Clock
SYS
2
/ ÷40 )
Periodic/interval
Trigger Event
for Q1 and Q2
SAR Control
SAR[9:0]
QCLK
14-49