Renesas R8C/15 Información técnica Pagina 92

  • Descarga
  • Añadir a mis manuales
  • Imprimir
  • Pagina
    / 279
  • Tabla de contenidos
  • MARCADORES
  • Valorado. / 5. Basado en revisión del cliente
Vista de pagina 91
R8C/14 Group, R8C/15 Group 12. Watchdog Timer
Rev.2.10 Jan 19, 2006 Page 78 of 253
REJ09B0164-0210
12. Watchdog Timer
The watchdog timer is a function to detect when the program is out of control. To use the watchdog timer is
recommend for improving reliability of a system. The watchdog timer contains a 15-bit counter and can
select count source protection mode is enabled or disabled. Table 12.1 lists the Count Source Protection
Mode is Enabled / Disabled
Refer to 5.5 Watchdog Timer Reset for details of the watchdog timer reset.
Figure 12.1 shows the Block Diagram of Watchdog Timer and Figures 12.2 to 12.3 show the OFS, WDC,
WDTR, WDTS and CSPR Registers.
Figure 12.1 Block Diagram of Watchdog Timer
Table 12.1 Count Source Protection Mode is Enabled / Disabled
Item
When Count Source Protection
Mode is Disabled
When Count Source Protection
Mode is Enabled
Count Source CPU clock Low-speed on-chip oscillator
clock
Count Operation Decrement
Reset Condition of Watchdog
Timer
Reset
Write “00h” to the WDTR register before writing “FFh”
Underflow
Count Start Condition Either of following can be selected
After reset, count starts automatically
Count starts by writing to WDTS register
Count Stop Condition Stop mode, wait mode None
Operation at the time of
Underflow
Watchdog timer interrupt or
watchdog timer reset
Watchdog timer reset
CPU Clock
1/16
1/128
Watchdog Timer
Internal
Reset Signal
Write to WDTR register
WDC7=0
WDC7=1
Set to
“7FFFh”
(1)
PM12=1
Watchdog
Timer Reset
PM12=0
Watchdog Timer
Interrupt Request
Prescaler
CSPRO=0
fRING-S
CSPRO=1
CSPRO : Bit in CSPR register
WDC7 : Bit in WDC register
NOTES:
1. When the CSPRO bit is set to “1” (count source protection mode enabled), “0FFFh” is set.
Vista de pagina 91
1 2 ... 87 88 89 90 91 92 93 94 95 96 97 ... 278 279

Comentarios a estos manuales

Sin comentarios