5-3

STANDARD AND PTS INTERRUPTS
Figure 5-1 illustrates the interrupt processing flow. In this flow diagram, “INT_MASK” repre-sents both the INT_MASK and INT_MAS K1 registers, and “INT_PEND” repre sents both theINT_PEND and INT_PEND1 registers.5.2 INTERRUPT SIGNALS AND REGISTERSTable 5-1 describes the external interrupt signals and Table 5-2 describe s the cont rol and statu sregisters for both the interrupt controller and PTS.

Table 5-1. Interrupt Signals

Port Pin Interrupt Signal Type Description
EXTINT I External Interrupt
This programmable int errupt is controlled by the
WG_PROTECT register. This register controls whether the
interrupt is edge triggered or sampled and whether a risin g
edge/high level or falling edge/low level act ivate s the
interrupt.
In powerdown mode, asserting the EXT INT signal for at least
50 ns causes the device to re sume normal o peration. The
interrupt need not be enabled. If the EXTINT interrupt is
enabled, the CPU executes the interrupt service routine.
Otherwise, the CPU executes the instruct ion that immediately
follows the command that i nvoked the power-saving mode .
In idle mode, asse rting any enabled int errupt causes the
device to resume normal ope ration.
NMI I Nonmaskable Interrup t
In normal operating mode, a rising edge on NMI generates a
nonmaskable interrupt. NMI has the highe st priority o f all
prioritized interrupts. A ssert NMI for greater than o ne state
time to guarantee that it is recognized.

Table 5-2. Interrupt and PTS Control and Status Registers

Mnemonic Address Description
INT_MASK
INT_MASK1
0008H
0013H
Interrupt Mask Reg isters
These registers enable/disable each maskable interrupt (that is,
each interrupt ex cept unimplemented op code, software trap, an d
NMI).
INT_PEND
INT_PEND1
0009H
0012H
Interrupt Pending Re gisters
The bits in this register are set by hardware to indicate that an
interrupt is pending.
PI_MASK 1FBCH Peripheral Interrupt Ma sk
The bits in this register ena ble and disable (mask) the tim er 1 and 2
overflow/underflow int errupt requests, the waveform generator
interrupt request (MC, MD), the EPA compare-only channel 5
interrupt request (MD), and the serial port error i nterrupts (MH).