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Chapter 7
Interrupt/Exception Processing Function
User’s Manual U16580EE3V1UD00
7.3.6 In-service priority register (ISPR)
The ISPR register holds the priority level of the maskable interrupt currently acknowledged. When an
interrupt request is acknowledged, the bit of this register corresponding to the priority level of that
interrupt request is set to 1 and remains set while the interrupt is serviced.
When the RETI instruction is executed, the bit corresponding to the interrupt request having the highest
priority is automatically reset to 0 by hardware. However, it is not reset to 0 when execution is returned
from non-maskable interrupt servicing or exception processing.
Reset input clears this register to 00H.
This register is read-only, in 8-bit or 1-bit units.
Caution:
In the interrupt enabled (EI) state, if an interrupt is acknowledged during the reading
of the ISPR register, the value of the ISPR register may be read after the bit is set (1)
by this interrupt acknowledgment. To read the value of the ISPR register properly
before interrupt acknowledgment, read it in the interrupt disabled (DI) state.
Figure 7-13:
Interrupt Service Priority Register (ISPR)
Remark:
n = 0 to 7 (priority level)
After reset:
00H
R
Address:
FFFFF1FAH
7
6
5
4
3
2
1
0
ISPR
ISPR7
ISPR6
ISPR5
ISPR4
ISPR3
ISPR2
ISPR1
ISPR0
ISPRn
Priority of Interrupt Currently Being Acknowledged
0
Interrupt request with priority n is not acknowledged
1
Interrupt request with priority n is being acknowledged
Summary of Contents for MuPD70F3187
Page 6: ...6 Preface User s Manual U16580EE3V1UD00 ...
Page 16: ...16 User s Manual U16580EE3V1UD00 ...
Page 28: ...28 User s Manual U16580EE3V1UD00 ...
Page 32: ...32 User s Manual U16580EE3V1UD00 ...
Page 84: ...84 Chapter 2 Pin Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 144: ...144 Chapter 3 CPU Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 312: ...312 Chapter 9 16 Bit Timer Event Counter P User s Manual U16580EE3V1UD00 MEMO ...
Page 534: ...534 Chapter 11 16 bit Timer Event Counter T User s Manual U16580EE3V1UD00 ...
Page 969: ...969 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 970: ...970 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 ...
Page 976: ...976 Chapter 22 Internal RAM Parity Check Function User s Manual U16580EE3V1UD00 MEMO ...
Page 984: ...984 Chapter 23 On Chip Debug Function OCD User s Manual U16580EE3V1UD00 MEMO ...
Page 1006: ...1006 Chapter 24 Flash Memory User s Manual U16580EE3V1UD00 MEMO ...
Page 1036: ...1036 Chapter 27 Recommended Soldering Conditions User s Manual U16580EE3V1UD00 MEMO ...
Page 1046: ...1046 Appendix A Index User s Manual U16580EE3V1UD00 MEMO ...
Page 1052: ...1052 User s Manual U16580EE3V1UD00 ...
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