MC68HC912DG128 Datasheet, PDF (186/452 Pages) Motorola, Inc – Microcontrollers

Clock Functions
Freescale Semiconductor, Inc.
RTBYP — Real Time Interrupt Divider Chain Bypass
Write not allowed in normal modes, anytime in special modes. Read
anytime.
0 = Divider chain functions normally.
1 = Divider chain is bypassed, allows faster testing (the divider
chain is normally XCLK divided by 2¹³, when bypassed
becomes XCLK divided by 4).
RTR2, RTR1, RTR0 — Real-Time Interrupt Rate Select
Read and write anytime.
Rate select for real-time interrupt. The clock used for this module is
the XCLK.
Table 11-4. Real Time Interrupt Rates
RTR2
0
0
0
0
1
1
1
1
RTR1
0
0
1
1
0
0
1
1
RTR0
Divide X By:
Time-Out Period
X = 125 KHz
Time-Out Period
X = 500 KHz
Time-Out Period
X = 2.0 MHz
Time-Out Period
X = 8.0 MHz
0
OFF
OFF
OFF
OFF
OFF
1
2¹³
65.536 ms
16.384 ms
4.096 ms
1.024 ms
0
2¹⁴
131.72 ms
32.768 ms
8.196 ms
2.048 ms
1
2¹⁵
263.44 ms
65.536 ms
16.384 ms
4.096 ms
0
2¹⁶
526.88 ms
131.72 ms
32.768 ms
8.196 ms
1
2¹⁷
1.05 s
263.44 ms
65.536 ms
16.384 ms
0
2¹⁸
2.11 s
526.88 ms
131.72 ms
32.768 ms
1
2¹⁹
4.22 s
1.05 s
263.44 ms
65.536 ms
Bit 7
6
5
4
3
2
1
Bit 0
RTIF
0
0
0
0
0
0
0
RESET:
0
0
0
0
0
0
0
0
RTIFLG — Real Time Interrupt Flag Register
$0015
RTIF — Real Time Interrupt Flag
This bit is cleared automatically by a write to this register with this bit
set.
0 = Time-out has not yet occurred.
1 = Set when the time-out period is met.
Technical Data
186
MC68HC912DG128 — Rev 3.0
Clock Functions
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