BS85B12-3 HOLTEK [Holtek Semiconductor Inc], BS85B12-3 Datasheet - Page 50

• Manufacturer Part Number: BS85B12-3
• Description: Touch Key Flash Type 8-Bit MCU with LCD/LED Driver
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

Rev. 1.00
Reset Initial Conditions
Note:
Watchdog Time-out Reset during Normal Operation
Watchdog Time-out Reset during SLEEP or IDLE Mode
The Watchdog time-out Reset during normal operation is the same as a hardware power-on reset
except that the Watchdog time-out flag TO will be set to 1 .
The Watchdog time-out Reset during SLEEP or IDLE Mode is a little different from other kinds of
reset. Most of the conditions remain unchanged except that the Program Counter and the Stack Pointer
will be cleared to 0 and the TO flag will be set to 1 . Refer to the A.C. Characteristics for t
The t
LIRC.
The different types of reset described affect the reset flags in different ways. These flags, known as
PDF and TO are located in the status register and are controlled by various microcontroller operations,
such as the SLEEP or IDLE Mode function or Watchdog Timer. The reset flags are shown in the table:
Note: u stands for unchanged
The following table indicates the way in which the various components of the microcontroller are af-
fected after a power-on reset occurs.
Program Counter
Interrupts
WDT
Timer Modules
Input/Output Ports
Stack Pointer
TO
0
u
1
1
SST
is 15~16 clock cycles if the system clock source is provided by HIRC. The t
PDF
Item
0
u
u
1
Touch Key Flash MCU with LCD/LED Driver
WDT Time-out Reset during SLEEP or IDLE Timing Chart
WDT Time-out Reset during Normal Operation Timing Chart
Power-on reset
LVR reset during NORMAL or SLOW Mode operation
WDT time-out reset during NORMAL or SLOW Mode operation
WDT time-out reset during IDLE or SLEEP Mode operation
Note: t
Reset to zero
All interrupts will be disabled
Clear after reset, WDT begins counting
Timer Counter will be turned off
I/O ports will be setup as inputs
Stack Pointer will point to the top of the stack
RSTD
is power-on delay, typical time=100ms
RESET Conditions
44
Condition After RESET
BS85B12-3/BS85C20-3
SST
February 1, 2011
is 1~2 clock for
SST
details.