mc68hc912bc32 Freescale Semiconductor, Inc, mc68hc912bc32 Datasheet - Page 120

• Manufacturer Part Number: mc68hc912bc32
• Description: M68hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Clock Generation Module (CGM)
FCOP — Force COP Watchdog Reset Bit
DISR — Disable Resets from COP Watchdog and Clock Monitor Bit
CR2, CR1, and CR0 — COP Watchdog Timer Rate Select Bit
10.7.5 Arm/Reset COP Timer Register
Always reads $00.
Writing $55 to this address is the first step of the COP watchdog sequence.
Writing $AA to this address is the second step of the COP watchdog sequence. Other instructions may
be executed between these writes but both must be completed in the correct order prior to timeout to
avoid a watchdog reset. Writing anything other than $55 or $AA causes a COP reset to occur.
120
Writes are not allowed in normal modes; can be written anytime in special modes.
If DISR is set, this bit has no effect.
Writes are not allowed in normal modes, anytime in special modes.
The COP system is driven by a constant frequency of E/2
but two stages of this divider to be bypassed for testing in special modes only.) These bits specify an
additional division factor to arrive at the COP timeout rate. The clock used for this module is the E
clock.
Write once in normal modes, anytime in special modes.
0 = Normal operation
1 = Force a COP reset, if COP is enabled.
0 = Normal operation
1 = Regardless of other control bit states, COP and clock monitor do not generate a system reset.
CR2
Address: $0017
0
0
0
0
1
1
1
1
Reset:
Read:
Write:
CR1
0
0
1
1
0
0
1
1
Figure 10-9. Arm/Reset COP Timer Register (COPRST)
Bit 7
Bit 7
0
Table 10-4. COP Watchdog Rates (RTBYP = 0)
CR0
0
1
0
1
0
1
0
1
Bit 6
6
0
M68HC12B Family Data Sheet, Rev. 9.1
Divide E By:
OFF
2
2
2
2
2
2
2
Bit 5
13
15
17
19
21
22
23
5
0
Bit 4
4
0
At E = 4.0-MHz
0 to +2.048 ms
131.072 ms
524.288 ms
8.1920 ms
32.768 ms
2.048 ms
Timeout
1.048 s
2.097 s
OFF
Bit 3
13
3
0
. (RTBYP in the RTICTL register allows all
Bit 2
2
0
At E = 8.0-MHz
0 to +1.024 ms
262.144 ms
524.288 ms
1.048576 s
Bit 1
16.384 ms
65.536 ms
1.024 ms
4.096 ms
Timeout
1
0
OFF
Freescale Semiconductor
Bit 0
Bit 0
0