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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 EI
2
OS.
■ 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 independent operation mode or the 8 + 8-bit PPG output 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 "00
H
" to "FF
H
", an underflow
occurs. When an underflow occurs, the underflow generation flag bit in the channel causing an
underflow is set (PPGC
n
: PUF0=1 or PPGC
m
: PUF1=1).
• If an interrupt request from the channel that causes an underflow is enabled (PPGC
n
: PIE0=1 or
PPGC
m
: 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 "0000
H
" to "FFFF
H
", an underflow occurs. When an underflow occurs, the underflow
generation flag bits in the two channels are set at one time (PPGC
n
: PUF0=1 or PPGC
m
: PUF1=1).
• When an underflow occurs with either of the two channel of the interrupt requests enabled (PPGC
n
:
PIE1=0, PPGC
m
: PIE1=1 or PPGC
n
: PIE0=1, PPGC
m
: 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 (PPGC
n
: PIE0=0, PPGC
m
: PIE1=1 or PPGC
n
: PIE0=1, PPGC
m
: PIE1=0).
• When the two channels of the underflow generation flag bits are set (PPGC
n
: PUF0=1 and PPGC
m
:
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