HD6433308 HITACHI [Hitachi Semiconductor], HD6433308 Datasheet - Page 262

• Manufacturer Part Number: HD6433308
• Description: Hitachi Single-Chip MicroComputer
• Manufacturer: HITACHI [Hitachi Semiconductor]

14.1 Overview
The H8/330 has a power-down state that greatly reduces power consumption by stopping some or
all of the chip functions. The power-down state includes three modes:
(1) Sleep mode – a software-triggered mode in which the CPU halts but the rest of the chip
(2) Software standby mode – a software-triggered mode in which the entire chip is inactive
(3) Hardware standby mode – a hardware-triggered mode in which the entire chip is inactive
Table 14-1 lists the conditions for entering and leaving the power-down modes. It also indicates the
status of the CPU, on-chip supporting modules, etc. in each power-down mode.
Table 14-1. Power-Down State
Mode
Sleep
mode
Soft-
ware
standby
mode
Hard-
ware
standby
mode
Notes
1. SYSCR: System control register
2. SSBY:
3. On-chip supporting modules, including the dual-port RAM.
remains active
Entering
procedure
Execute
SLEEP
instruction
Set SSBY bit
in SYSCR to
“1,” then
execute SLEEP
instruction
Set STBY
pin to Low
level
Software standby bit
Section 14. Power-Down State
Clock CPU
Run
Halt
Halt
Halt
Halt
Halt
CPU
Reg’s. Mod.* RAM
Held
Held
Not
held
253
Sup.
Run
Halt
and
initial-
ized
Halt
and
initialized
Held
Held
Held
I/O
ports
Held
Held
High
impe-
dance
state
Exiting
methods
• Interrupt
• RES
• STBY
• NMI
• IRQ
• STBY
• RES
• STBY High,
then RES
Low
0
– IRQ
High
2