SN8F2250B Series
USB 2.0 Full-Speed 8-Bit Micro-Controller
5
SYSTEM OPERATION MODE
5.1 OVERVIEW
The chip is featured with low power consumption by switching around four different modes as following.
z
z
z
z
High-speed mode
Low-speed mode
Power-down mode (Sleep mode)
Green mode
Power Down Mode
(Sleep Mode)
P0, P1 Wake-up Function Active.
USB Bus.
CPUM1, CPUM0 = 01.
External Reset Circuit Active.
CLKMD = 1
CLKMD = 0
Normal Mode
Slow Mode
P0, P1 Wake-up Function Active.
T0 Timer Time Out.
CPUM1, CPUM0 = 10.
P0, P1 Wake-up Function Active.
T0 Timer Time Out.
USB Bus.
USB Bus.
External Reset Circuit Active.
Green Mode
External Reset Circuit
Active.
System Mode Switching Diagram
Operating mode description
POWER DOWN
MODE
NORMAL
SLOW
GREEN
REMARK
(SLEEP)
EHOSC
ILRC
CPU instruction
T0 timer
Running
Running
Executing
*Active
*Active
*Active
By STPHX
Running
Executing
*Active
*Active
*Active
By STPHX
Running
Stop
Stop
Stop
Stop
Inactive
Inactive
Inactive
Inactive
Inactive
*Active
* Active if T0ENB=1
* Active if T1ENB=1
* Active if TC0ENB=1
* Active if TC1ENB=1
* Active if USBE=1
T1 timer
Inactive
Inactive
Inactive
Inactive
TC0 timer
TC1 timer
USB
*Active
Running
*Active
Inactive
By Watch_Dog By Watch_Dog By Watch_Dog By Watch_Dog Refer to code option
Watchdog timer
Code option
All active
All active
Code option
All active
All active
Code option
Code option
All inactive
All inactive
description
Internal interrupt
External interrupt
T0
All active
P0, P1, T0,
Reset
Wakeup source
-
-
P0, P1, Reset
z
z
EHOSC: External high clock (External X’tal)
ILRC: Internal low clock (24KHz RC oscillator)
SONiX TECHNOLOGY CO., LTD
Page 52
Version 1.1
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