QADC64E Enhanced Mode Operation
MPC561/MPC563 Reference Manual, Rev. 1.2
14-50
Freescale Semiconductor
14.4.6
Periodic/Interval Timer
The on-chip periodic/interval timer can be used to generate trigger events at a programmable interval,
initiating execution of queue 1 and/or queue 2. The periodic/interval timer stays reset under the following
conditions:
•
Both queue 1 and queue 2 are programmed to any mode which does not use the periodic/interval
timer
•
IMB3 system reset or the master reset is asserted
•
Stop mode is selected
•
Freeze mode is selected
NOTE
Interval timer single-scan mode does not use the periodic/interval timer
until the single-scan enable bit is set.
The following two conditions will cause a pulsed reset of the periodic/interval timer during use:
•
A queue 1 operating mode change to a mode which uses the periodic/interval timer, even if queue
2 is already using the timer
•
A queue 2 operating mode change to a mode which uses the periodic/interval timer, provided queue
1 is not in a mode which uses the periodic/interval timer
•
Roll over of the timer
During the low power stop mode, the periodic timer is held in reset. Since low power stop mode causes
QACR1 and QACR2 to be reset to zero, a valid periodic or interval timer mode must be written after stop
mode is exited to release the timer from reset.
When the IMB3 internal FREEZE line is asserted and a periodic or interval timer mode is selected, the
timer counter is reset after the conversion in progress completes. When the periodic or interval timer mode
has been enabled (the timer is counting), but a trigger event has not been issued, the freeze mode takes
effect immediately, and the timer is held in reset. When the internal FREEZE line is negated, the timer
counter starts counting from the beginning. Refer to
Section 14.4.7, “Configuration and Control Using the
” for more information.
Table 14-22. QADC64E Clock Programmability
Control Register 0 Information
Input Sample Time (IST) =0
Example
Number
Frequency
PRESCALER
QCLK
(MHz)
Conversion Time
(
µ
s)
1
20 MHz
0x09
2.0
7.0
2
40 MHz
0x13
2.0
7.0
3
56 MHz
0x1B
2.0
7.0
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...