HT82M99E-18 HOLTEK [Holtek Semiconductor Inc], HT82M99E-18 Datasheet - Page 11

• Manufacturer Part Number: HT82M99E-18
• Description: USB Mouse Encoder 8-Bit OTP MCU
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

wake-up event occurs, it takes 1024 t
period) to resume normal operation. In other words, a
dummy period will be inserted after a wake-up. If the
wake-up results from an interrupt acknowledge signal,
the actual interrupt subroutine execution will be delayed
by one or more cycles. If the wake-up results in the next
instruction execution, this will be executed immediately
after the dummy period is finished.
To minimize power consumption, all the I/O pins should
be carefully managed before entering the HALT status.
Reset
There are four ways in which a reset can occur:
The WDT time-out during HALT is different from other
chip reset conditions, since it can perform a warm re -
set that resets only the PC and SP, leaving the other cir-
cuits in their original state. Some registers remain un-
changed during other reset conditions. Most registers
are reset to the initial condition when the reset condi-
tions are met. By examining the PDF and TO flags, the
program can distinguish between different chip resets .
Note: u stands for unchanged
To guarantee that the system oscillator is started and
stabilized, the SST (System Start-up Timer) provides an
extra delay of 1024 system clock pulses when the sys-
tem resets (power-up, WDT time-out or RES reset) or
the system awakes from the HALT state.
When a system reset occurs, the SST delay is added
during the reset period. Any wake-up from HALT will en-
able the SST delay.
Rev. 1.50
TO PDF
RES reset during normal operation
RES reset during HALT
WDT time-out reset during normal operation
USB reset
0
u
0
1
1
0
u
1
u
1
RES reset during power-up
RES reset during normal operation
RES wake-up HALT
WDT time-out during normal operation
WDT wake-up HALT
RESET Conditions
SYS
(system clock
11
The functional unit chip reset status are shown below.
PC
Interrupt
Prescaler
WDT
Timer/event Counter Off
Input/output Ports
Stack Pointer
Reset Configuration
Reset Timing Chart
Reset Circuit
000H
Disable
Clear
Clear. After master reset, WDT
begins counting
Input mode
Points to the top of the stack
November 19, 2004
HT82M99E