
3-5
ML63326 User's Manual
Chapter 3 CPU Control Functions
3
3.3.3 Melody Data Interrupt and Halt Mode Release
The halt mode is not released by a melody data interrupt.
The melody data interrupt is different from a conventional interrupt in that the melody data
interrupt is a hardware processing interrupt used for transfer of melody data to the melody
circuit. It is not dependent on the program.
When this interrupt is generated, the instruction immediately after the HALT instruction is
executed, then the melody data is transferred to the melody circuit, and the HALT instruction
is executed again. This sequence is indicated in Figure 3-6.
S1
S2
S1
S2
S1
S2
S1
S2
S1
S2
S1
S2
S2
S2
S2
HALT
HALT
instruction
execution
n
HLT (halt flag)
Melody data
request
PC flow in main
routine
: HALT instruction address
: Melody data address
Halt mode
Halt mode
HALT
Melody
data
transfer
HALT
instruction
execution
(melody)
Execution of
instruction
immediately after
HALT instruction
n
System Clock
n+1
n+1
n
(melody)
Figure 3-6 Melody Data Request Interrupt Operation
3.3.4 Note Concerning HALT Instruction
As described above, the instruction immediately after the HALT instruction may be executed
any number of times. For this reason, always place an NOP instruction immediately after the
HALT instruction.
(Example)
•
•
•
HALT
NOP
•
•
•
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 ...