Fujitsu FR81S User Manual
CHAPTER 17: PPG
6. Notes
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER
: PPG
FUJITSU SEMICONDUCTOR CONFIDENTIAL
65
6. Notes
This section explains notes of the PPG.
Note the following when using the PPG:
PPG Operation Activation
1. The first load delays up to 2.5T after the activation trigger (T: Count clock). If an operation that loads a
value to the down counter and another operation that decrements the counter occur at the same time, the
first operation takes precedence (overwrites the down counter).
trigger
PPG
X
0003
0002
0001
0000
0003
0002
Load
clock
Count value
Varid edge
Duty match
Counter borrow
interrupt
max 2.5T
2. To activate the PPG, the timer operation enable bit (PCN:CNTE) must be set to "1" before or when PPG
operation is enabled.
3. The PPG activation with an internal trigger is the same operation as the PPG activation using a software
trigger or an external trigger (TRG pin).
Beforehand, it is necessary to set the register necessary for the PPG operation.
PPG is Operating
4. During the PPG operation, do not change any of the following: the mode selection bit (PCN:MDSE), the
restart enable bit (PCN:RTRG), the counter clock selection bits (PCN:CKS1, CKS0), the trigger input edge
selection bits (PCN:EGS1, EGS0), the interrupt factor selection bits (PCN:IRS1, IRS0), the activation
trigger selection bits (GTRS:TSEL[6:0]), and the PPG output polarity selection bit (PCN:OSEL).
If any of the above bits is changed during the PPG operation, disable PPG operation before reconfiguring
the register.
5. If the timer operation enable bit (PCN:CNTE) is set to "0" to disable the PPG during the PPG operation,
the PPG stops with its state (count and output level) maintained.
Thereafter, to restart the PPG, set the timer operation enable bit (PCN:CNTE) to "1" to enable the PPG and
reload the cycle and the duty values by entering an activation trigger.
6. If the timer operation enable bit (PCN:CNTE) is set to "0" to disable the PPG, it takes 3 clocks in internal
clock until the PPG output is stopped.
Valid edge
MB91520 Series
MN705-00010-1v0-E
606