ML610471/472/473/Q471/Q472/Q473 User's Manual
Chapter 4 MCU Control Function
4-9
4.3 Description of Operation
4.3.1 Program Run Mode
The program run mode is the state where the CPU executes instructions sequentially.
At power-on reset, low-speed oscillation stop detect reset, WDT overflow reset, or RESET_N pin reset, the CPU
executes instructions from the addresses that are set in addresses 0002H and 0003H of program memory (ROM) after the
system reset mode is released.
At reset by the BRK instruction, the CPU executes instructions from the addresses that are set in the addresses 0004H
and 0005H of the program memory after the system reset mode is released. However, when the value of the interrupt
level bit (ELEVEL) of the program status word (PSW) is 02H or higher at execution of the BRK instruction (after the
occurrence of the WDT interrupt), the CPU executes instructions from the addresses that are set in the addresses 0002H
and 0003H.
For details of the BRK instruction and PSW, see the “nX-U8/100 Core Instruction Manual” and for the reset function,
see Chapter 3, “Reset Function”.
4.3.2 HALT Mode
The HALT mode is the state where the CPU interrupts execution of instructions and only the peripheral circuits are
running.
When the HLT bit of the standby control register (SBYCON) is set to “1”, the HALT mode is set.
When a WDT interrupt request, or an interrupt request enabled by an interrupt enable register (IE1–IE7) is issued, the
HLT bit is set to “0” on the falling edge of the next system clock (SYSCLK) and the HALT mode is returned to the
program run mode released.
Figure 4-2 shows the operation waveforms in HALT mode.
CPUCLK
システムクロック
SYSCLK
プログラム動作モード
HALT
モード
割込み要求
プログラム動作モード
SBYCON.HLT
Figure 4-2 Operation Waveforms in HALT Mode
Note:
Since up to two instructions are executed during the period between HALT mode release and a transition to interrupt
processing, place two NOP instructions next to the instruction that sets the HLT bit to “1”.
System clock
Interrupt request
Program run mode
HALT mode
Program run mode
Содержание ML610472
Страница 12: ...Chapter 1 Overview...
Страница 38: ...Chapter 2 CPU and Memory Space...
Страница 44: ...Chapter 3 Reset Function...
Страница 48: ...Chapter 4 MCU Control Function...
Страница 62: ...Chapter 5 Interrupts...
Страница 82: ...Chapter 6 Clock Generation Circuit...
Страница 94: ...Chapter 7 Time Base Counter...
Страница 105: ...Chapter 8 Capture...
Страница 114: ...Chapter 9 Timer...
Страница 133: ...Chapter 10 Watchdog Timer...
Страница 141: ...Chapter 11 UART...
Страница 164: ...Chapter 12 Port 0...
Страница 173: ...Chapter 13 Port 2...
Страница 180: ...Chapter 14 Port 3...
Страница 188: ...Chapter 15 Port 4...
Страница 199: ...Chapter 16 Port 6...
Страница 205: ...Chapter 17 RC Oscillation Type A D Converter...
Страница 225: ...Chapter 18 LCD Drivers...
Страница 243: ...Chapter 19 Power Supply Circuit...
Страница 245: ...Chapter 20 uEASE Flash Writer System...
Страница 249: ...Chapter 21 Software Development...
Страница 258: ...Appendixes...
Страница 280: ...Revision History...