Technical information

APPLICATION
2.2 Timer
2-19
3800 GROUP USER’S MANUAL
Control procedure :
Figure 2.2.19 shows a control procedure.
Fig. 2.2.19 Control procedure [Measurement of frequency]
RTI
(A) TY (Address : 2716)
TY
IREQ1
(Address : 2716)
(Address : 3C
16), bit5
256 – 1
0
0
Fpulse 0
Fpulse 1
Processing for a result of judgment
214 (A) 228?
< <
Compare the count value read with the
reference value.
Store the comparison result in flag Fpulse.
Out of range
In range
●
●
●
●
●
●
Pop registers
Pop registers which is pushed to stack.
●
Read the count value.
Store the count value in the accumulator (A).
Initialize the count value.
Set the Timer Y interrupt request bit to “0.”
RESET
Initialization
SEI
TM
PRE12
T1
PREY
TY
ICON1
TM
CLI
....
....
....
(Address : 2316)
(Address : 20
16)
(Address : 21
16)
(Address : 26
16)
(Address : 27
16)
(Address : 3E
16), bit6
(Address : 23
16), bit7
1110XXXX
2
64–1
8–1
1–1
256–1
1
1
Timer 1 interrupt processing routine
IREQ1 (Address : 3C16), bit5?
●
●
●
●
●
●
●
Set the division ratio so that the Timer 1 interrupt
occurs every 2 ms.
Timer 1 interrupt : Enabled
●
Note 1: When using the Index X mode flag (T).
Note 2: When using the Decimal mode flag (D).
Push the register used in the interrupt
processing routine into the stack.
● X : This bit is not used in this application.
Set it to
“0” or “1.” It’s value can be disregarded.
0
When the count value is 256 or more, the
processing is performed as out of range.
Timer Y : Event counter mode
(Count at falling edge of pulse input from CNTR
1 pin)
All interrupts : Disabled
Timer Y count : Start
Interrupts : Enabled
CLT (Note 1)
CLD (Note 2)
Push register to stack