Epson RX8111CE, Руководство по применению

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RX8111CE
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24 ETM61E-01
14.2. Wake-up Timer Interrupt Function
The wake-up timer interrupt function generates an interrupt event periodically at any fixed cycle set between 244.14

s and 31.9
years. This function can stop at one time and is available as an accumulative timer.
After the interrupt occurs, the /INT status is automatically cleared .
14.2.1. Related registers for function of wake-up timer interrupt function
Table 16 Wake-up interrupt timer register
Address Function bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
1Ah Timer Counter 0 128 64 32 16 8 4 2 1
1Bh Timer Counter 1 32768 16384 8192 4096 2048 1024 512 256
1Ch Timer Counter 2
8388608 4194304
2097152 1048576
524288
262144 131072 65536
1Dh Extension Register FSEL1 FSEL0 USEL TE WADA ETS TSEL1 TSEL0
1Eh Flag Register POR z UF TF AF EVF VLF XST
1Fh Control Register z z UIE TIE AIE EIE z STOP
2Dh Timer Control z z z z TBKON TBKE TMPIN TSTP
Before entering operation settings, we recommend first clearing the TE bit to "0" .
When the fixed-cycle timer function is not being used, the fixed-cycle Timer Counter0,1 register can be used as a RAM register. In
such cases, stop the fixed-cycle timer function by writing "0" to the TE and TIE bits.
1) Down counter for wake-up interrupt timer Timer Counter 2, 1, 0
This register is used to set the default (preset) value for the counter. Any count value from 1 (000001h) to 16777216 (FFFFFFh) can
be set.
Be sure to write "0" to the TE bit before writing the preset value.
When TE = 0, read out data of timer counter is default (Preset) value. And when TE = 1, read out data of timer counter is just
counting value. But, when access to timer counter data, counting value is not held.
Therefore, for example, perform twice read access to obtain right data, and a way to adopt the case that two data accorded is
necessary.
2) TSEL1, TESL0 bit
This combination decides the source clock of count down period.
The source clock selection should
be done after TE bit setting to “0”.
Table 17 TSEL bit, selection of source clock
TSEL1
(bit 1)
TSEL0
(bit 0)
Source clock
Auto reset time
(tRTN)
0 0
4096 Hz Once per 244.14

s 122

s
0 1
64 Hz Once per 15.625 ms 7.813 ms
1 0 1 Hz Once per 1 second 7.813 ms
1 1
1/60 Hz
Once per minute
7.813 ms
The /INT pin's auto reset time (tRTN) varies as shown above according to the source clock setting.
The first countdown shortens than a source clock.
The example of the error of the first countdown: A value to preset is 0004h
Cycle error
TE
Designed cycle
正しい周期
Inner source clock
TF bit
”0”
⇒
“1”
TF
3 2 1 4
Down counter
4
Figure 18 Wake-up timer initial sequence (cycle error)