UPD17073 NEC, UPD17073 Datasheet - Page 94

no-image

UPD17073

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

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
UPD17073GB-572-1A7-A
Manufacturer:
RENESAS
Quantity:
16 435
Basic timer 1
interrupt pulse
IRQBTM1 flag
IPBTM1 flag
INTE FF
12.3.3 Error of basic timer 1
pulse falls, if the EI instruction has been executed, and if the interrupt has been enabled.
94
As described in 12.3.2, the interrupt generated by basic timer 1 is accepted each time the basic timer 1 interrupt
Therefore, an error of basic timer 1 occurs only when any of the following operations are performed:
• When the first interrupt after basic timer 1 interrupt has been enabled has been accepted
• When the time interval at which the IRQBTM1 flag is to be set is changed, i.e., when the first interrupt is accepted
• When data has been written to the IRQBTM1 flag
Figure 12-9 shows an error in each of the above operations.
after the interrupt pulse has been changed
(a) When interrupt by basic timer 1 is enabled
At point <1> in the above figure, the interrupt by basic timer 1 is accepted as soon as the interrupt is
enabled.
At this time, the error is –t
If an interrupt is enabled by the “EI” instruction at the next point <3>, the interrupt occurs at the falling edge
of the basic timer 1 interrupt pulse.
At this time, the error is:
–t
SET
< error < 0
DI
EI
H
L
1
0
1
0
Interrupt pending
Figure 12-9. Error of Basic Timer 1 (1/2)
SET
EI
.
SET1 IPBTM1
Interrupt accepted
<1> <2>
t
SET
EI
<3>
Interrupt accepted
EI
PD17072,17073
Interrupt accepted

Related parts for UPD17073