Fujitsu FR81S User Manual
CHAPTER 17: PPG
6. Notes
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER
: PPG
FUJITSU SEMICONDUCTOR CONFIDENTIAL
69
39. Notes the following when rewriting the cycle value (PHCSR/PLCSR) and the duty value
(PHDUT/PLDUT) in the PPG communication mode.
(1) The cycle value (PHCSR/PLCSR) and the duty value (PHDUT/PLDUT) will be transferred from the
register to the counter when an activation trigger is generated or when a borrow occurs. Therefore, if the
cycle (PHCSR/PLCSR) or duty value (PHDUT/PLDUT) is rewritten during the PPG communication
operation, the new value will be effective on the output waveform after the cycle next to the cycle after
the borrow occurs.
(2) The duty value (PHDUT/PLDUT) must be equal to or smaller than the cycle value
(PHCSR/PLCSR).
If the duty value is set larger than the cycle value (PHCSR/PLCSR), disable PPG communication
operation before changing the duty value (PHDUT/PLDUT) to a smaller value. If PPG communication
operation is not disabled, the following will occur:
⋅
The output level will be "H" or "L" depending on [the cycle value (PHCSR/PLCSR) < the duty
value (PHDUT/PLDUT)] setting. (The output level selects "H" or "L" by the PPG output polarity
selection (OSEL) setting.)
(3) If the cycle value (PHCSR/PLCSR) and the duty value (PHDUT/PLDUT) are set to the same value,
or if the duty value (PHDUT/PLDUT) set to "0", the following will occur:
⋅
When setting as cycle = duty:
If the polarity is normal (OSEL=0), the output is "H".
If the polarity is inverted (OSEL=1), the output is "L".
⋅
When setting as duty = 0:
If the polarity is normal (OSEL=0), the output is "H" in 1 cycle of count clock.
If the polarity is inverted (OSEL=1), the output is "L" in 1 cycle of count clock.
30. When accessing the High/Low format cycle setting register (PHCSR/PLCSR) and the duty setting
register (PHDUT/PLDUT) of the PPG communication mode, be sure to use 16-bit format. If these registers
are accessed in byte format, the values are not written at an upper and lower bit positions.
31. When the PPG communication is continuously executed, rewriting PPG communication mode data
(PCMDDT) is needed during the PPG communication operation. (Even if the same value is written, the
PPG communication is executed.)
However, after the bit length according to PCMDWD (PPG communication mode data bit length) setting is
output, the next setting data is output.
MB91520 Series
MN705-00010-1v0-E
610