UPD17073 NEC, UPD17073 Datasheet - Page 93

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

12.3.2 Application example of basic timer 1
and that the IRQBTM1 flag is set to 1 even in the DI status.
the “RETI” instruction, if processing A takes longer than 8 ms.
A program example is shown below.
Example
This program executes processing A every 80 ms.
The points to be noted in this case are that the DI status is automatically set when an interrupt has been accepted,
This means that the interrupt is accepted even if execution exits from an interrupt service routine by execution of
Consequently, processing B is not executed.
M1
BTIMER1 DAT
ORG
EI_RETI:
START:
LOOP:
MEM
BR
BTIMER1
ADD
SKT1
BR
MOV
EI
RETI
MOV
BANK1
SET1
SET1
EI
BANK0
BR
Processing A
Processing B
0.10H
0002H
START
M1, #0001B
CY
EI_RETI
M1, #0110B
M1, #0110B
BTM1CK
IPBTM1
LOOP
; 80-ms counter
; Symbol definition of basic timer 1 interrupt vector address
; Branches to START
; Program address (0002H)
; Adds 1 to M1
; Tests CY flag
; Returns if no carry
; Initializes contents of M1 to 6
; Embedded macro
; Sets basic timer 1 interrupt pulse to 8 ms
; Enables basic timer 1 interrupt
; Enables all interrupts
PD17072,17073
93