UPD17073 NEC, UPD17073 Datasheet - Page 96

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

12.3.4 Notes on using basic timer 1
intervals by using the basic timer 1 after the supply voltage has been once applied (power-ON reset), the basic timer
1 interrupt service must be completed in a fixed time.
BTM0CY flag setting pulse.
at this time, CE reset takes precedence.
processing is skipped once.
96
When creating a program, such as a program for watch, in which processing is always performed at fixed time
Let’s take the following example:
Example
In this example, processing B is executed every 80 ms while processing A is executed.
If the CE pin goes high as shown in Figure 12-10, CE reset is effected in synchronization with the rising of the
If issuance of an interrupt request by the basic timer 1 happens to overlap with the setting of the BTM0CY flag
When CE reset is effected, the basic timer 1 interrupt request (IRQBTM1) flag is cleared. Consequently, the timer
M1
BTIMER1 DAT
ORG
EI_RETI:
START:
LOOP:
; <1>
MEM
BR
BTIMER1
ADD
SKT1
BR
MOV
EI
RETI
MOV
BANK1
SET1
SET1
EI
BR
Processing B
Processing A
0.10H
0002H
START
M1, #0001B
CY
EI_RETI
M1, #0110B
M1, #0110B
BTM1CK
IPBTM1
LOOP
; 80-ms counter
; Symbol definition of interrupt vector address of basic timer 1
; Branches to START
; Program address (0002H)
; Adds 1 to M1
; Watch processing if carry occurs
; Restores if no carry occurs
; Initializes contetns of M1 to 6
; Embedded macro
; Sets time of interrupt by basic timer 1 to 8 ms
; Embedded macro
; Enables interrupt by basic timer 1
; Enables all interrupts
PD17072,17073