UPD17073 NEC, UPD17073 Datasheet - Page 173

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

19.2.6 Releasing halt status by interrupt
the halt status is to be released must be specified by software.
status has been released differs.
is executed after the interrupt has been serviced, the program returns to the next instruction after the HALT instruction.
after the HALT instruction is executed as soon as the halt status has been released.
interrupt are described below.
(1) The “HALT 1000B” instruction is set.
(2) Each interrupt is enabled by the corresponding interrupt enable flag (IP
(3) An interrupt request is issued by the corresponding interrupt request flag (IRQ
To release the halt status by interrupt, use the “HALT 1000B” instruction.
There are three interrupt sources available as explained in 11. INTERRUPT. Therefore, the interrupt by which
The halt status is released if the following conditions (1) through (3) are satisfied:
Depending on whether the EI or DI instruction is executed at this time, the operation to be performed after the halt
If the EI instruction is executed, the program branches to the vector address of the interrupt. If the RETI instruction
If the DI instruction is executed, the program does not branch to a vector address, but the next instruction next
Examples of programs when the EI and DI instruction are executed, and notes on releasing the halt status by
flag = 1).
PD17072,17073
flag = 1).
173