Zilog Z80180 - Manual (Page 52)

Z8018x
Family MPU User Manual
UM005003-0703
37
STANDBY Mode
The Z8S180/Z8L180 is designed to save power. Two low-power
programmable power-down modes have been added:
•
STANDBY mode
•
IDLE mode
The STANDBY/IDLE mode is selected by multiplexing bits 1 and 3 of
the CPU Control Register (CCR, I/O Address =
1FH
).
To enter STANDBY mode:
Table 5. Power-Down Modes (Z8S180/Z8L180-Class Processors Only)
Power-
Down
Modes
CPU Core
On-Chip
I/O
Osc. CLKOUT
Recovery
Source Recovery Time
(Minimum)
SLEEP Stop Running Running Running RESET,
Interrupts 1.5 Clock
I/O STOP Running Stop Running Running By
Programming –
SYSTEM
STOP Stop Stop Running Running RESET,
Interrupts 1.5 Clock
IDLE † Stop Stop Running Stop RESET,
Interrupts,
BUSREQ 8 + 1.5 Clock
STANDBY † Stop Stop Stop Stop RESET,
Interrupts,
BUSREQ 2 17 + 1.5 Clock
(Normal
Recovery)
2
6
+ 1.5 Clock
(Quick Recovery)
† IDLE and STANDBY modes are only offered in the Z8S180. The minimum recovery time can
be achieved if INTERRUPT is used as the Recovery Source.