UPD17073 NEC, UPD17073 Datasheet - Page 85

• Manufacturer Part Number: UPD17073
• Description: 4-BIT SINGLE-CHIP MICROCONTROLLER WITH HARDWARE FOR DIGITAL TUNING SYSTEM
• Manufacturer: NEC

12.2.4 Error of basic timer 0
to be set (refer to 12.2.5 Notes on using basic timer 0).
BTM0CY flag is to be set (125 ms) is t
The time at which the BTM0CY flag is to be detected must be shorter than the time at which the BTM0CY flag is
Where the time interval at which the BTM0CY flag is to be detected is t
At this time, as shown in Figure 12-3, the timer error when the BTM0CY flag is detected is:
As shown in Figure 12-3, the timer is updated because the BTM0CY flag is detected as “1” in <2>.
In <3>, the flag is “0”; therefore, the timer is not updated until the BTM0CY flag is detected again in <4>.
At this time, the time of the timer is extended by t
t
0 < error < t
CHECK
BTM0CY flag
setting pulse
BTM0CY flag
< t
Figure 12-3. Error of Basic Timer 0 due to Detection Time of BTM0CY Flag
SET
SET
H
L
1
0
SET
SKT1
BTM0CY
<1>
, the relation between t
t
SET
t
CHECK1
CHECK3
SKT1
BTM0CY
<2>
.
CHECK
t
CHECK2
and t
SKT1
BTM0CY
<3>
CHECK
SET
must be as follows:
and the time interval at which the
t
CHECK3
PD17072,17073
SKT1
BTM0CY
<4>
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