UPD78F0138 NEC, UPD78F0138 Datasheet - Page 386

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

(2) HALT mode release
386
The HALT mode can be released by the following two sources.
(a) Release by unmasked interrupt request
When an unmasked interrupt request is generated, the HALT mode is released. If interrupt
acknowledgement is enabled, vectored interrupt servicing is carried out. If interrupt acknowledgement is
disabled, the next address instruction is executed.
Remarks 1. The broken lines indicate the case when the interrupt request which has released the standby
or subsystem clock
Ring-OSC clock,
X1 input clock,
Status of CPU
release signal
2. The wait time is as follows:
Standby
mode is acknowledged.
• When vectored interrupt servicing is carried out:
• When vectored interrupt servicing is not carried out: 2 or 3 clocks
Figure 19-3. HALT Mode Release by Interrupt Request Generation
Operating mode
instruction
CHAPTER 19 STANDBY FUNCTION
HALT
User’s Manual U16228EJ2V0UD
HALT mode
Interrupt
request
Oscillation
Wait
Wait
8 or 9 clocks
Operating mode