Texas Instruments MSC1210 - Manual (Page 121)

Waking Up from Idle Mode
10-15
Interrupts
a millisecond interrupt will be provoked every 20ms. This assumes and re-
quires that MSECH (FD
H
) and MSECL (FC
H
) are set to values that represent
a millisecond. If MSECH and MSECL are set to other values, the frequency
at which the millisecond interrupt occurs will vary proportionally.
The seconds interrupt functions in a manner similar to the millisecond inter-
rupt, but can be used to provoke an interrupt at reduced frequencies, on the
order of seconds. For the seconds interrupt to be provoked once per second,
MSECH and MSECL must be set to values that represent a millisecond, and
HMSEC (FE
H
) must be set to a value that represents 1/100th of a second. If
any of these three SFRs are assigned different values, the frequency of the
seconds interrupt will vary proportionally.
10.8.5.4 ADC Conversion Interrupt
The ADC conversion interrupt is triggered whenever an ADC conversion pro-
duces a new result in the ADRESH/M/L SFRs. When an ADC conversion inter-
rupt is triggered or signaled, the user program can read the new result from
these SFRs. The interrupt is cleared by reading the LSB of the sample data
(ADRESL).
10.8.5.5 Summation Register Interrupt
When the summation mode is set to modes 1 (sum values from the ADC) or
3 (sum for SCNT times, then shift SHFT times), an interrupt will occur at the
end of the process. Note that an interrupt will not occur in modes 0 and 2. The
interrupt is cleared by reading the LSB of the summation registers (SUMR0).
10.9 Waking Up from Idle Mode
When the MSC1210 is placed in idle mode, three events and the auxiliary inter-
rupts can optionally wake up the microcontroller. The three events are: a
watchdog interrupt, external interrupt 1, or external interrupt 0. Which inter-
rupt(s) wakes up the MSC1210 is determined by the Enable Wake Up (EWU,
E8
H
) SFR.
Table 10−13. EWU (C6
H
) SFR
Bit Name Explanation of Function
7 − Undefined
6 − Undefined
5 − Undefined
4 − Undefined
3 − Undefined
2 EWUWDT Wake Up on Watchdog Timer
1 EWUEX1 Wake Up on External Interrupt 1
0 EWUEX0 Wake Up on External Interrupt 0
Setting each of the bits in this SFR will allow the MSC1210 to wake up from
idle mode when the corresponding interrupt occurs. If the corresponding bit is
clear, the specified interrupt will not cause the MSC1210 to wake up from idle
mode.