7 OSCILLATOR CIRCUIT (OSC)
S1C17001 TECHNICAL MANUAL
EPSON
63
7.7 RESET and NMI Input Noise Filters
Since accidental activation of RESET or NMI by noise in the S1C17 core input signal will cause unintended reset-
ting or NMI processing, the OSC module incorporates noise filters operated by the system clock. The filters remove
noise from these signals before they reach the S1C17 core.
Separate noise filters are used for each signal. You can select to use or bypass them individually. All are active im-
mediately after the initial resetting.
RESET input noise filter: Filters noise when RSTFE (D1/OSC_NFEN register) = 1; bypassed when RSTFE = 0
NMI input noise filter: Filters noise when NMIFE (D0/OSC_NFEN register) = 1; bypassed when NMIFE = 0
∗
RSTFE
: Reset Noise Filter Enable Bit in the Noise Filter Enable (OSC_NFEN) Register (D1/0x5062)
∗
NMIFE
: NMI Noise Filter Enable Bit in the Noise Filter Enable (OSC_NFEN) Register (D0/0x5062)
The noise filters operate using the system clock (OSC3 or OSC1 clock) divided to 1/8. When activated, they filter
out noise with pulses not exceeding two clock cycles.
This means the pulse width must be at least 16 cycles of the system clock to input as a valid signal.
Note: • All noise filters should normally be enabled.
• The S1C17001 does not feature external NMI input pins, but the watchdog timer NMI re-
quest signal passes through these filters.
Summary of Contents for S1C17001
Page 1: ...Technical Manual S1C17001 CMOS 16 BIT SINGLE CHIP MICROCONTROLLER ...
Page 33: ...4 POWER SUPPLY VOLTAGE 24 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 63: ...6 INITERRUPT CONTROLLER 54 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 87: ...8 CLOCK GENERATOR CLG 78 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 91: ...9 PRESCALER PSC 82 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 133: ...11 16 BIT TIMER T16 124 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 211: ...16 STOPWATCH TIMER SWT 202 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 219: ...17 WATCHDOG TIMER WDT 210 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 241: ...18 UART 232 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 277: ...20 I2 C 268 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 313: ...25 PACKAGE 304 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...