ht82m73e Holtek Semiconductor Inc., ht82m73e Datasheet - Page 21

• Manufacturer Part Number: ht82m73e
• Description: 2.4ghz Mouse Tx 8-bit Otp Mcu
• Manufacturer: Holtek Semiconductor Inc.

Note:
Oscillator
There are four oscillator circuits contained within the de-
vice. The first and second is the system oscillator which
utilities an external crystal or external RC circuit and the
third and fourth is the Watchdog timer and Built_in RC
timer. Both of Watchdog timer and Built_in RC timer are
fully integrated and require no external components.
The PC.3 bit is used to select the system clock source. If
PC.3 is set high then the system clock will be sourced
from the external crystal otherwise it will be sourced from
the Built_in RC timer. Bit PB.7 is used to indicate whether
the external crystal or Built_in RC is in operation.
Built_in RC Timer Oscillator
The Built_in RC timer oscillator is a fully self-contained free
running on-chip RC oscillator with a typical frequency of
1MHz at 5V requiring no external components.
System Clock Configurations
There are two oscillator mode Crystal and RC. For Crys-
tal mode no built-in capacitor between OSC1, OSC2
and GND. The simple connection of a crystal across
OSC1 and OSC2 will create the necessary phase shift
and feedback for oscillation, without requiring external
capacitors. However, for some crystal types and fre-
Rev. 1.00
PCL
MP
ACC
TBLP
TBLH
STATUS
INTC
TMRL
TMRH
TMRC
PA
PAC
PB
PBC
PC
PCC
PD
PDC
Register
* means warm reset
- not implemented
u means unchanged
x means unknown
(Power-on)
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
-000 0000
00-0 1000
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
-xxx xxxx
--00 xxxx
Reset
000H
(Normal Operation)
WDT time-out
uuuu uuuu
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1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
-uuu uuuu
-000 0000
00-0 1000
--1u uuuu
xxxx xxxx
xxxx xxxx
000H
21
(Normal Operation)
quencies, to ensure oscillation, it may be necessary to
add two small value capacitors, C1 and C2. Using a ce-
ramic resonator will usually require two small value ca-
pacitors, C1 and C2, to be connected as shown for
oscillation to occur. The values of C1 and C2 should be
selected in consultation with the crystal or resonator
manufacturer's specification. In most applications, re-
sistor R1 is not required, however for those applications
RES Reset
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uuuu uuuu
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
-uuu uuuu
-000 0000
00-0 1000
--uu uuuu
xxxx xxxx
xxxx xxxx
000H
Crystal/Ceramic Oscillator
RC Oscillator
RES Reset
uuuu uuuu
uuuu uuuu
uuuu uuuu
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
-uuu uuuu
-000 0000
00-0 1000
--00 uuuu
xxxx xxxx
xxxx xxxx
(HALT)
000H
HT82M73E
WDT Time-out
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
-uuu uuuu
-uuu uuuu
uu-u uuuu
--11 uuuu
May 14, 2008
(HALT)*
000H