mc68hc11ea9 Freescale Semiconductor, Inc, mc68hc11ea9 Datasheet - Page 24

• Manufacturer Part Number: mc68hc11ea9
• Description: 8-bit Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

COPRST — Arm/Reset COP Timer Circuitry
HPRIO — Highest Priority I-Bit Interrupt and Miscellaneous
RBOOT — Read Bootstrap ROM
SMOD — Special Mode Select
MDA — Mode Select A
IRVNE — Internal Read Visibility/Not E
PSEL[3:0] — Priority Select Bit 4 through Bit 0
24
RESET:
RESET:
Write $55 to COPRST to arm COP watchdog circuit. Write $AA to COPRST to reset COP watchdog
circuit.
*RBOOT, SMOD, and MDA reset depend on power-up initialization mode and can only be written in
special mode.
Refer to 4.4 Bootstrap Mode
Refer to 4.5 Mode Selection
Refer to 4.5 Mode Selection
Refer to 4.5 Mode Selection
Can be written only while the I-bit in the CCR is set (interrupts disabled). These bits select one interrupt
source to be elevated above all other I-bit related sources.
RBOOT*
BIT 7
BIT 7
—
7
0
CR[1:0]
SMOD*
0 0
0 1
1 0
1 1
—
6
6
0
6
Freescale Semiconductor, Inc.
For More Information On This Product,
Selected
2
2
2
2
MDA*
Table 8 COP Timer Rate Selection
Rate
15
17
19
21
—
5
5
0
5
E
E
E
E
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IRVNE
4
4
1
4
0
E = 1.0 MHz E = 2.0 MHz E = 3.0 MHz
131.072 ms
524.288 ms
32.768 ms
2.097 s
PSEL3
3
3
0
3
0
Period Length
262.140 ms
16.384 ms
65.536 ms
1.049 s
PSEL2
2
2
0
2
1
10.923 ms
43.691 ms
174.76 ms
699.05 ms
PSEL1
1
1
0
1
0
MC68HC11EA9TS/D
PSEL0
BIT 0
BIT 0
0
0
1
MC68HC11EA9
$103A
$103C