257
Chapter 8
Clock Generator
User’s Manual U16580EE3V1UD00
8.3.2 HALT
mode
(1)
Setting and operation status
The HALT mode is set when a dedicated instruction (HALT) is executed in the normal operation
mode.
When HALT mode is set, clock supply is stopped to the CPU only. The clock generator and PLL
continue operating. Clock supply to the other on-chip peripheral functions continues.
As a result, program execution is stopped, and the internal RAM retains the contents before the
HALT mode was set. The on-chip peripheral functions that are independent of instruction
processing by the CPU continue operating.
Table 18-3 shows the operation status in the HALT mode.
The average power consumption of the system can be reduced by using the HALT mode in
combination with the normal operation mode for intermittent operation.
Cautions: 1. Insert five or more NOP instructions after the HALT instruction.
2. If the HALT instruction is executed while an interrupt request is being held
pending, the HALT mode is set but is released immediately by the pending
interrupt request.
Table 8-1:
Operation Status in HALT Mode
Function
Operation Status
Clock generator
Operating
Internal system clock (f
XX
)
Supplied
CPU
Stopped
DMA
Operating
Interrupt controller
Operating
Ports
Maintained
On-chip peripheral I/O (excluding ports)
Operating
Internal data
All internal data such as CPU registers, states,
data, and the contents of internal RAM are
retained in the state they were before HALT mode
was set.
A0 to A21
Operating
D0 to D31
RD
WR
BEN0 to BEN3
CS0, CS1, CS3, CS4
WAIT
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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