Datasheet

Clock Module
MC68HC812A4 Data Sheet, Rev. 7
106 Freescale Semiconductor
RTIE — Real-Time Interrupt Enable Bit
Write: Anytime
RTIE enables interrupt requests generated by the RTIF flag.
1 = RTIF interrupt requests enabled
0 = RTIF interrupt requests disabled
RSWAI — RTI Stop in Wait Bit
Write: Once in normal modes, anytime in special modes
RSWAI disables the RTI and the COP during wait mode.
1 = RTI and COP disabled in wait mode
0 = RTI and COP enabled in wait mode
RSBCK — RTI Stop in Background Mode Bit
Write: Once in normal modes, anytime in special modes
RSBCK disables the RTI and the COP during background debug mode.
1 = RTI and COP disabled during background mode
0 = RTI and COP enabled during background mode
RTBYP — RTI Bypass Bit
Write: Never in normal modes, anytime in special modes
RTBYP allows faster testing by causing the divider chain to be bypassed. The divider chain normally
divides M by 2
13
. When RTBYP is set, the divider chain divides M by 4.
1 = Divider chain bypass
0 = No divider chain bypass
RTR2, RTR1, RTR0 — Real-Time Interrupt Rate Select Bits
Write: Anytime
Rate select for real-time interrupt. The clock used for this module is the module (M) clock.
Table 10-2. Real-Time Interrupt Rates
RTR[2:1:0] M-Clock Divisor
Real-Time Timeout Period
M = 4.0 MHz M = 8.0 MHz
000 Off Off Off
001
2
13
2.048 ms 1.024 ms
010
2
14
4.096 ms 2.048 ms
011
2
15
8.196 ms 4.096 ms
100
2
16
16.384 ms 8.196 ms
101
2
17
32.768 ms 16.384 ms
110
2
18
65.536 ms 32.768 ms
111
2
19
131.72 ms 65.536 ms