Z86L82 Datasheet, PDF (65/80 Pages) Maxim Integrated Products – 28-Pin Low-Voltage IR Microcontrollers

Z86L82/85/88
28-Pin Low-Voltage IR Microcontrollers
58
The POR time is a nominal 5 ms. Bit 5 of the Stop-Mode Register determines
whether the POR timer is bypassed after Stop-Mode Recovery (typical for external
clock, RC, and LC oscillators).
HALT
HALT turns off the internal CPU clock, but not the XTAL oscillation. The counter/
timers and external interrupts IRQ0, IRQ1, IRQ2, IRQ3, and IRQ4 remain active.
The devices are recovered by interrupts, either externally or internally generated.
An interrupt request must be executed (enabled) to exit HALT Mode. After the
interrupt service routine, the program continues from the instruction after the
HALT.
STOP
This instruction turns off the internal clock and external crystal oscillation and
reduces the standby current to 10 mA or less. STOP Mode is terminated only by a
reset (such as WDT time-out), POR, SMR, or external reset. This termination
causes the processor to restart the application program at address 000CH. To
enter STOP (or HALT) mode, you need to first flush the instruction pipeline to
avoid suspending execution in mid-instruction. To execute this action, you must
execute a NOP (op code = FFH) immediately before the appropriate sleep instruc-
tion. For example:
FF
NOP
6F
STOP
; clear the pipeline
; enter STOP Mode
or
FF
NOP
7F
HALT
; clear the pipeline
; enter HALT Mode
PS009007-1202