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CHAPTER 16 8-/16-BIT PPG TIMER
16.4 Interrupts of 8-/16-bit PPG Timer
The 8-/16-bit PPG timer can generate an interrupt request when the PPG down counter
underflows. It also not corresponds to the EI2OS.
■Interrupts of 8-/16-bit PPG Timer
Table 16.4-1 shows the interrupt control bits and interrupt factor of the 8-/16-bit PPG timer.
Note: n = C, E m = n + 1
[8-bit PPG output 2-channel independent operation mode or 8 + 8-bit PPG output operation mode]
• In the 8-bit PPG output 2-channel indepe ndent operatio n mode or the 8 + 8-bit PPG outpu t operation
mode, the PPGn and PPGm timers can generate an interrupt independently.
• When the value of the PPGn or PPGm down counter is decremented from "00H" to "FFH", an underflow
occurs. When an underflow occurs, the underflow generation flag bit in the channel causing an
underflow is set (PPGCn: PUF0=1 or PPGCm: PUF1=1).
• If an interrupt request from the channel that causes an underflow is enabled (PPGCn: PIE0=1 or
PPGCm: PIE1=1), an interrupt request is generated.
[16-bit PPG output operation mode]
• In the 16-bit PPG output operation mode, when the values of the PPGn and PPGm down counters are
decremented from "0000H" to "FFFFH", an underflow occurs. When an underflow occurs, the underflow
generation flag bits in the two channels are set at one time (PPGCn: PUF0=1 or PPGCm: PUF1=1).
• When an underflow occurs with either of the two channel of the interrupt requests enabled (PPGCn:
PIE1=0, PPGCm: PIE1=1 or PPGCn: PIE0=1, PPGCm: PIE0=0), an interrupt request is generated.
• To prevent duplication of interrupt requests, disable either of the two channel of the underflow interrupt
enable bits in advance (PPGCn: PIE0=0, PPGCm: PIE1=1 or PPGCn: PIE0=1, PPGCm: PIE1=0).
• When the two channels of the underflow generation flag bits are set (PPGCn: PUF0=1 and PPGCm:
PUF1=1), clear the two channels at the same time.
■Interrupt of 8-/16-bit PPG Timer
For details of the interrupt number, interrupt control register, and interrupt vector address, see "CHAPTER
3 INTERRUPTS".
Table 16.4-1 Interrupt Control Bits of 8-/16-bit PPG Timer
PPGn PPGm
Interrupt request flag bit PPGCn: PUF0 PPGCm: PUF1
Interrupt request enable bit PPGCn: PIE0 PPGCm: PIE1
Interrupt factor Underflow in PPGn down counter Underflow in PPGm down counter