HT48RA0-5 Holtek Semiconductor, HT48RA0-5 Datasheet - Page 10

• Manufacturer Part Number: HT48RA0-5
• Description: Remote Type 8-Bit OTP MCU
• Manufacturer: Holtek Semiconductor

Reset
There are several ways in which a reset can occur:
Some registers remain unchanged during reset condi-
tions. Most registers are reset to the initial condition
when the reset conditions are met. By examining the
PDF and TO flags, the program can distinguish between
different chip resets.
Note: u means unchanged.
Rev.1.00
Power On reset
RES pin reset
Low Voltage reset
WDT time-out reset during normal operation
TO
0
u
1
1
PDF
0
u
u
1
Reset Configuration
Reset Timing Chart
Power-on reset
RES or LVR reset during normal
operation
WDT time-out reset during normal
operation
WDT time-out reset during
power-down mode
RESET Conditions
10
Note:
To guarantee that the system oscillator has started and
stabilized, the SST (System Start-up Timer) provides an
extra-delay of 1024 system clock pulses when the sys-
tem powers up or when the system awakes from a HALT
state.
When a system power up occurs, an SST delay is added
during the reset period. Any wake-up from HALT will en-
able the SST delay.
The functional unit chip reset status is shown below.
* Determined by configuration option
Program Counter
WDT Prescaler
Input/Output ports
Stack Pointer
Carrier output
added for added ESD protection
added in environments where power line noise
is significant.
* It is recommended that this component is
** It is recommended that this component is
External RES Circuit
000H
Clear
Input mode
Points to the top of the stack
Low level state or floating
state*
HT48RA0-5
March 23, 2010
www.DataSheet4U.com