Operating Status After Debugging Break Occurs - Epson S1C17704 Technical Manual

24 ON-CHIP DEBUGGER (DBG)

24.2 Operating Status after Debugging Break Occurs

When the brk instruction is executed or a break signal (low) is input to the DSIO pin, a debug interrupt occurs and
the S1C17 Core enters debug mode. This status continues until the retd instruction is executed.
In debug mode, hardware interrupts and NMI cannot be accepted.
By default, the peripheral modules are stopped in debug mode. This status can be changed so that they will operate
during debugging.
The LCD driver continues in operating status when a debug interrupt occurs during debugging.
Peripheral modules that operate with a prescaler output clock
• 8-bit timer
• 16-bit timers
• PWM & capture timer
• Remote controller
• P ports
• UART
• SPI
2
• I C
By default, the prescaler stops in debug mode. Therefore, the peripheral modules listed above are also stopped
as they use a prescaler output clock. The prescaler provides PRUND (D1/PSC_CTL register) for specifying
prescaler operating condition in debug mode. When PRUND is set to 1, the prescaler operates in debug mode.
This allows the above peripheral modules to operate. When PRUND is 0 (default), the prescaler and above
peripheral modules stop operating when the S1C17 Core enters debug mode.
∗ PRUND: Prescaler Run/Stop Setting (in Debug Mode) Bit in the Prescaler Control (PSC_CTL) Register
(D1/0x4020)
Peripheral modules that operate with the OSC1 clock
• Clock timer
• Watchdog timer
• Stopwatch timer
The MISC register provides O1DBG (D0/MISC_OSC1 register) to specify the operating condition for the
OSC1 peripheral modules (listed above) in debug mode. When O1DBG is set to 1, the OSC1 peripheral
modules operate in debug mode. When O1DBG is 0 (default), the OSC1 peripheral modules stop operating
when the S1C17 Core enters debug mode.
∗ O1DBG: OSC1 Peripheral Control (in Debug Mode) Bit in the OSC1 Peripheral Control (MISC_OSC1)
Register (D0/0x5322)
Note that the 8-bit OSC1 timer does not stop in debug mode even if O1DBG is set to 1.
24-2
EPSON
S1C17704 TECHNICAL MANUAL