
3-4
ML63326 User's Manual
Chapter 3 CPU Control Functions
3.3.2 Halt Mode Release
The following two methods are available to release the halt mode.
• Release by interrupt generation (transfer to normal operation mode)
• Release by RESET pin (transfer to system reset mode)
3.3.2.1 Release of Halt Mode by Interrupt
If the halt mode is to be released by an interrupt, the enable flag of the interrupt used for
release must be set to "1" prior to entering the halt mode. When the halt mode is released by
an interrupt, operation transfers to the normal operation mode.
Figure 3-5 shows the timing of transferring to the halt mode by execution of a HALT instruction
and of releasing the halt mode by an interrupt.
When the halt mode is released by an interrupt request, the first instruction immediately
following the HALT instruction is executed and then the interrupt routine is entered. When an
RTI instruction is used to complete the interrupt routine, the main routine is resumed
beginning from the second instruction after the HALT instruction.
Figure 3-5 Timing of Transfer to Halt Mode and Release of Halt Mode by Interrupt
!
Note:
If the halt mode is to be released, set individual interrupt enable flags to "1". If an individual
interrupt enable flag is "0", the corresponding interrupt request signal cannot reset the HLT
flag, regardless of whether the master interrupt enable flag (MIE) is "0" or "1".
3.3.2.2 Release of Halt Mode by RESET Pin
If a high-level is input to the RESET pin, the CPU is released from the halt mode and transfers
to the system reset mode.
S1
S2
S1
S2
S1
S2
S1
S2
S1
S2
S1
S2
S1
S2
S1
S2
HALT
HLT (halt flag)
Interrupt request
INT
PC flow in main
routine
: HALT instruction address
: Starting address of interrupt routine
: RTI instruction address
HALT
instruction
execution
Halt mode
RTI
instruction
execution
Main
routine
Interrupt
routine
System clock
n
(RTI)
n+2
n+1
(INT)
n
(INT)
(RTI)
Execution of
instruction
immediately after
HALT instruction
Summary of Contents for ML63326
Page 3: ......
Page 13: ......
Page 14: ...Chapter 1 Overview 1 ...
Page 15: ......
Page 37: ...1 22 ML63326 User s Manual Chapter 1 Overview ...
Page 38: ...Chapter 2 CPU and Memory Spaces 2 ...
Page 39: ......
Page 50: ...CPU Control Functions Chapter 3 3 ...
Page 51: ......
Page 57: ...3 6 ML63326 User s Manual Chapter 3 CPU Control Functions ...
Page 58: ...Interrupt INT326 Chapter 4 4 ...
Page 59: ......
Page 71: ...4 12 ML63326 User s Manual Chapter 4 Interrupt INT326 ...
Page 72: ...Clock Generator Circuit OSC Chapter 5 5 ...
Page 73: ......
Page 83: ...5 10 ML63326 User s Manual Chapter 5 Clock Generator Circuit OSC ...
Page 84: ...Time Base Counter TBC Chapter 6 6 ...
Page 85: ......
Page 90: ...Timers TIMER Chapter 7 7 ...
Page 91: ......
Page 115: ...7 24 ML63326 User s Manual Chapter 7 Timers TIMER ...
Page 116: ...Chapter 8 8 100 Hz Timer Counter 100HzTC ...
Page 117: ......
Page 121: ...8 4 ML63326 User s Manual Chapter 8 100 Hz Timer Counter 100HzTC ...
Page 122: ...Chapter 9 9 Watchdog Timer WDT ...
Page 123: ......
Page 128: ...Chapter 10 10 Ports INPUT OUTPUT I O PORT ...
Page 129: ......
Page 170: ...Chapter 11 11 External Memory Transfer Function EXTMEM ...
Page 171: ......
Page 179: ...11 8 ML63326 User s Manual Chapter 11 External Memory Transfer Function EXTMEM ...
Page 180: ...Chapter 12 12 Melody Driver MELODY63K ...
Page 181: ......
Page 195: ...12 14 ML63326 User s Manual Chapter 12 Melody Driver MELODY63K ...
Page 196: ...13 Chapter 13 Voice Synthesis ...
Page 197: ......
Page 228: ...14 Chapter 14 Shift Register SFT ...
Page 229: ......
Page 236: ...15 Chapter 15 LCD Driver LCD ...
Page 237: ......
Page 250: ...16 Chapter 16 Battery Low Detect Circuit BLD ...
Page 251: ......
Page 255: ...16 4 ML63326 User s Manual Chapter 16 Battery Low Detect Circuit BLD ...
Page 256: ...Chapter 17 17 Power Supply Circuit POWER ...
Page 257: ......
Page 260: ...Appendixes ...
Page 261: ......
Page 321: ...Appendix 60 ML63326 User s Manual Appendix G ...