mc68hc11d0 Freescale Semiconductor, Inc, mc68hc11d0 Datasheet - Page 44

• Manufacturer Part Number: mc68hc11d0
• Description: Mc68hc11d0 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

OPTION — System Configuration Options
4.2.2.3 OPTION Register
Bits [7:6] and 2 — Not implemented
IRQE — IRQ Select Edge Sensitive only
DLY — Enable Oscillator Startup Delay
CME — Clock Monitor Enable
CR[1:0] — COP Timer Rate Select Bits
4-10
RESET:
The 8-bit special-purpose OPTION register sets internal system configuration options
during initialization. The time protected control bits, IRQE, DLY, and CR[1:0] can be
written to only once after a reset and then they become read-only. This minimizes the
possibility of any accidental changes to the system configuration.
*Can be written only once in first 64 cycles out of reset in normal modes, or at any time in special modes
Always read zero
Refer to SECTION 5 RESETS AND INTERRUPTS.
The internal E clock is first divided by 2
These control bits determine a scaling factor for the watchdog timer. Refer to SEC-
TION 5 RESETS AND INTERRUPTS.
0 = IRQ is configured for level sensitive operation
1 = IRQ is configured for edge sensitive only operation
0 = The oscillator startup delay coming out of STOP is bypassed and the MCU re-
1 = A delay of approximately 4000 E-clock cycles is imposed as the MCU is started
sumes processing within about four bus cycles.
up from the STOP power-saving mode. This delay allows the crystal oscillator
to stabilize.
Bit 7
0
0
Freescale Semiconductor, Inc.
6
0
0
OPERATING MODES AND ON-CHIP MEMORY
For More Information On This Product,
IRQE*
Go to: www.freescale.com
5
0
DLY*
15
4
1
before it enters the COP watchdog system.
CME
3
0
2
0
0
CR1*
TECHNICAL DATA
1
0
$0039
CR0*
Bit 0
0