XC912BC32CFU8 Motorola Semiconductor Products, XC912BC32CFU8 Datasheet - Page 74
![no-image](/images/no-image-200.jpg)
XC912BC32CFU8
Manufacturer Part Number
XC912BC32CFU8
Description
M68HC12B Family Data Sheet
Manufacturer
Motorola Semiconductor Products
Datasheet
1.XC912BC32CFU8.pdf
(362 pages)
- Current page: 74 of 362
- Download datasheet (5Mb)
Resets and Interrupts
4.6.3 Computer Operating Properly (COP) Reset
4.6.4 Clock Monitor Reset
4.7 Effects of Reset
4.7.1 Operating Mode and Memory Map
4.7.2 Clock and Watchdog Control Logic
4.7.3 Interrupts
Data Sheet
74
The MCU includes a COP system to help protect against software failures. When
COP is enabled, software must write $55 and $AA (in this order) to the COPRST
register to keep a watchdog timer from timing out. Other instructions may be
executed between these writes. A write of any value other than $55 or $AA or
software failing to execute the sequence properly causes a COP reset to occur.
If clock frequency falls below a predetermined limit when the clock monitor is
enabled, a reset occurs.
When a reset occurs, MCU registers and control bits are changed to known startup
states, as described here.
The states of the BKGD, MODA, and MODB pins during reset determine the
operating mode and default memory mapping. The SMODN, MODA, and MODB
bits in the MODE register reflect the status of the mode-select inputs at the rising
edge of reset. Operating mode and default maps can subsequently be changed
according to strictly defined rules.
Reset enables the COP watchdog with the CR2–CR0 bits set for the shortest
timeout period. The clock monitor is disabled. The RTIF flag is cleared and
automatic hardware interrupts are masked. The rate control bits are cleared and
must be initialized before the return-from-interrupt (RTI) system is used. The DLY
control bit is set to specify an oscillator startup delay upon recovery from stop
mode.
Reset initializes the HPRIO register with the value $F2, causing the IRQ pin to have
the highest I-bit interrupt priority. The IRQ pin is configured for level-sensitive
operation (for wired-OR systems). However, the I and X bits in the CCR are set,
masking IRQ and XIRQ interrupt requests.
Resets and Interrupts
M68HC12B Family — Rev. 8.0
MOTOROLA
Related parts for XC912BC32CFU8
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![T6410D](/images/no-image3.png)
Part Number:
Description:
Triacs
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![T6410](/images/no-image3.png)
Part Number:
Description:
Triacs
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![3N209](/images/no-image3.png)
Part Number:
Description:
6367254 Motorola SC (xstrs/r F)
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![BUT34](/images/no-image3.png)
Part Number:
Description:
50 Amperes NPN Silicon Power Darlington Transistor 850 Volts 250 Watts
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![3N202](/images/no-image3.png)
Part Number:
Description:
DUAL GATE Mosfet VHF Amplifier
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![3N201](/images/no-image3.png)
Part Number:
Description:
DUAL GATE Mosfet VHF Amplifier
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![MJD44E3](/images/no-image3.png)
Part Number:
Description:
NPN Darlington Silicon Power Transistor 10 Amperes 80 Volts 20 Watts
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![MC855](/images/no-image3.png)
Part Number:
Description:
Integrated Circuits
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![MC88913](/images/no-image3.png)
Part Number:
Description:
Low Skew CMOS Clock Driver
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![MC88914](/images/no-image3.png)
Part Number:
Description:
Low Skew CMOS Clock Driver With Reset
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![MSC7115](/images/no-image3.png)
Part Number:
Description:
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![MSC7116_08](/images/no-image3.png)
Part Number:
Description:
Low-cost 16-bit DSP with DDR Controller and 10/100 Mbps Ethernet MAC
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![MBR871](/images/no-image3.png)
Part Number:
Description:
Fast Recovery Power Rectifiers
Manufacturer:
Motorola Semiconductor Products
Datasheet:
![MBR872](/images/no-image3.png)
Part Number:
Description:
Fast Recovery Power Rectifiers
Manufacturer:
Motorola Semiconductor Products
Datasheet: