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INTERRUPTS
INTERRUPT REGISTERS (Cont’d)
EXTERNAL
INTERRUPT
PRIORITY
LEVEL
REGISTER (EIPLR)
R245 - Read/Write
Register Page: 0
Reset value: 1111 1111 (FFh)
Bit 7:6 = PL2D, PL1D:
INTD0, D1 Priority Level.
Bit 5:4 = PL2C, PL1C:
INTC0, C1 Priority Level.
Bit 3:2 = PL2B, PL1B:
INTB0, B1 Priority Level.
Bit 1:0 = PL2A, PL1A:
INTA0, A1 Priority Level.
These bits are set and cleared by software.
The priority is a three-bit value. The LSB is fixed by
hardware at 0 for Channels A0, B0, C0 and D0 and
at 1 for Channels A1, B1, C1 and D1.
EXTERNAL INTERRUPT VECTOR REGISTER
(EIVR)
R246 - Read/Write
Register Page: 0
Reset value: xxxx 0110b (x6h)
Bit 7:4 = V[7:4]:
Most significant nibble of External
Interrupt Vector.
These bits are not initialized by reset. For a repre-
sentation of how the full vector is generated from
V[7:4] and the selected external interrupt channel,
refer to Figure 1.
Bit 3 = TLTEV:
Top Level Trigger Event bit.
This bit is set and cleared by software.
0: Select falling edge as NMI trigger event
1: Select rising edge as NMI trigger event
Bit 2 = TLIS:
Top Level Input Selection.
This bit is set and cleared by software.
0: Watchdog End of Count is TL interrupt source
1: NMI is TL interrupt source
Bit 1 = IA0S:
Interrupt Channel A0 Selection.
This bit is set and cleared by software.
0: Watchdog End of Count is INTA0 source
1: External Interrupt pin is INTA0 source
Bit 0 = EWEN:
External Wait Enable.
This bit is set and cleared by software.
0: WAITN pin disabled
1: WAITN pin enabled (to stretch the external
memory access cycle).
Note: For more details on Wait mode refer to the
section describing the WAITN pin in the External
Memory Chapter.
NESTED INTERRUPT CONTROL (NICR)
R247 - Read/Write
Register Page: 0
Reset value: 0000 0000 (00h)
Bit 7 = TLNM:
Top Level Not Maskable.
This bit is set by software and cleared only by a
hardware reset.
0: Top Level Interrupt Maskable. A top level re-
quest is generated if the IEN, TLI and TLIP bits
=1
1: Top Level Interrupt Not Maskable. A top level
request is generated if the TLIP bit =1
Bit 6:0 = HL[6:0]:
Hold Level x
These bits are set by hardware when, in Nested
Mode, an interrupt service routine at level x is in-
terrupted from a request with higher priority (other
than the Top Level interrupt request). They are
cleared by hardware at the iret execution when
the routine at level x is recovered.
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PL2D PL1D PL2C PL1C PL2B PL1B PL2A PL1A
PL2x
PL1x
Hardware
bit
Priority
00
0
1
0 (Highest)
1
01
0
1
2
3
10
0
1
4
5
11
0
1
6
7 (Lowest)
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V7
V6
V5
V4
TLTEV TLIS IAOS EWEN
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TLNM HL6
HL5
HL4
HL3
HL2
HL1
HL0