Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.NET

X  

HT49C10-1 Datasheet(PDF) 11 Page - Holtek Semiconductor Inc

Part # HT49C10-1
Description  LCD Type 8-Bit MCU
Download  38 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  HOLTEK [Holtek Semiconductor Inc]
Direct Link  http://www.holtek.com
Logo HOLTEK - Holtek Semiconductor Inc

HT49C10-1 Datasheet(HTML) 11 Page - Holtek Semiconductor Inc

Back Button HT49C10-1 Datasheet HTML 7Page - Holtek Semiconductor Inc HT49C10-1 Datasheet HTML 8Page - Holtek Semiconductor Inc HT49C10-1 Datasheet HTML 9Page - Holtek Semiconductor Inc HT49C10-1 Datasheet HTML 10Page - Holtek Semiconductor Inc HT49C10-1 Datasheet HTML 11Page - Holtek Semiconductor Inc HT49C10-1 Datasheet HTML 12Page - Holtek Semiconductor Inc HT49C10-1 Datasheet HTML 13Page - Holtek Semiconductor Inc HT49C10-1 Datasheet HTML 14Page - Holtek Semiconductor Inc HT49C10-1 Datasheet HTML 15Page - Holtek Semiconductor Inc Next Button
Zoom Inzoom in Zoom Outzoom out
 11 / 38 page
background image
HT49R10A-1/HT49C10-1
Rev. 1.20
11
July 27, 2007
Oscillator Configuration
The device provides three oscillator circuits for system
clocks, i.e., RC oscillator, crystal oscillator and 32768Hz
crystal oscillator, determined by configuration options. No
matter what type of oscillator is selected, the signal is
used for the system clock. The HALT mode stops the sys-
tem oscillator (RC and crystal oscillator only) and ignores
external signals to conserve power. The 32768Hz crystal
oscillator (system oscillator) still runs when in the HALT
mode. If the 32768Hz crystal oscillator is selected as the
system oscillator, the system oscillator is not stopped; but
the instruction execution is stopped. Since the 32768Hz
oscillator is also designed for timing purposes, the inter-
nal timing (RTC, time base, WDT) operation still runs
even if the system enters the HALT mode.
Of the three oscillators, if the RC oscillator is used, an
external resistor between OSC1 and VSS is required,
and the range of the resistance should be from 24k
W to
1M
W. The system clock, divided by 4, is available on
OSC2 with a pull-high resistor, which can be used to
synchronize external logic. The RC oscillator provides
the most cost effective solution. However, the frequency
of the oscillation may vary with VDD, temperature, and
the chip itself due to process variations. It is therefore,
not suitable for timing sensitive operations where accu-
rate oscillator frequency is desired.
If the crystal oscillator is selected, a crystal across
OSC1 and OSC2 is needed to provide the feedback and
phase shift required for the oscillator, and no other ex-
ternal components are required. A resonator may be
connected between OSC1 and OSC2 to replace the
crystal and to get a frequency reference, but two exter-
nal capacitors on OSC1 and OSC2 are required.
There is another oscillator circuit designed for the real
time clock. In this case, only the 32.768kHz crystal oscil-
lator can be applied. The crystal should be connected
between OSC3 and OSC4.
The RTC oscillator circuit can be controlled to start up
quickly by setting the
²QOSC² bit (bit 4 of RTCC). It is
recommended to turn on the quick oscillating function
upon power on, and then turn it off after 2 seconds.
The WDT oscillator is a free running on-chip RC oscilla-
tor, and no external components are required. Although
the system enters the power down mode, the system
clock stops, and the WDT oscillator still works with a pe-
riod of approximately 65
ms at 5V. The WDT oscillator
can be disabled by configuration options to conserve
power.
Watchdog Timer
- WDT
The WDT clock source is implemented by a dedicated RC
oscillator (WDT oscillator) or an instruction clock (system
clock/4) or a real time clock oscillator (RTC oscillator). The
timer is designed to prevent a software malfunction or se-
quence from jumping to an unknown location with unpre-
dictable results. The WDT can be disabled by
configuration options. But if the WDT is disabled, all exe-
cutions related to the WDT lead to no operation.
The WDT time-out period is fS/2
15~f
S/2
16. If the WDT
clock source chooses the internal WDT oscillator, the
time-out period may vary with temperature, VDD, and
process variations. If the clock source selects the instruc-
tion clock and the
²HALT² instruction is executed, the
WDT may stop counting and lose its protecting purpose,
and the logic can only be restarted by external logic.
When the device operates in a noisy environment, using
the on-chip RC oscillator (WDT OSC) is strongly recom-
mended, since the HALT instruction will stop the system
clock.
The WDT overflow under normal operation initializes a
²chip reset² and sets the status bit ²TO². In the HALT
mode, the overflow initializes a
²warm reset², and only
the program counter and stack pointer are reset to zero.
To clear the contents of the WDT, there are three meth-
ods to be adopted, i.e., external reset (a low level to
RES), software instruction, and a
²HALT² instruction.
There are two types of software instructions;
²CLR
WDT
² and the other set -²CLR WDT1² and ²CLR
WDT2
². Of these two types of instruction, only one type
of instruction can be active at a time depending on the
options
-²CLR WDT² times selection option. If the ²CLR
WDT
² is selected (i.e., CLR WDT times equal one), any
execution of the
²CLR WDT² instruction clears the WDT.
In the case that
²CLR WDT1² and ²CLR WDT2² are cho-
sen (i.e., CLR WDT times equal two), these two instruc-
tions have to be executed to clear the WDT; otherwise,
the WDT may reset the chip due to a time-out.
C r y s t a l O s c i l l a t o r
R C O s c i l l a t o r
O S C 1
f S Y S / 4
O S C 2
V D D
3 2 7 6 8 H z C r y s t a l /
R T C O s c i l l a t o r
V D D
4 7 0 p F
O S C 3
O S C 4
O S C 1
O S C 2
System Oscillator


Similar Part No. - HT49C10-1

ManufacturerPart #DatasheetDescription
logo
Holtek Semiconductor In...
HT49C10-1 HOLTEK-HT49C10-1 Datasheet
239Kb / 37P
   LCD Type 8-Bit MCU
HT49C10-1 HOLTEK-HT49C10-1_12 Datasheet
258Kb / 38P
   LCD Type 8-Bit MCU
More results

Similar Description - HT49C10-1

ManufacturerPart #DatasheetDescription
logo
Holtek Semiconductor In...
HT49R30A-1 HOLTEK-HT49R30A-1_12 Datasheet
270Kb / 41P
   LCD Type 8-Bit MCU
HT49R50A-1 HOLTEK-HT49R50A-1 Datasheet
345Kb / 45P
   LCD Type 8-Bit MCU
HT49R70A-1 HOLTEK-HT49R70A-1 Datasheet
326Kb / 42P
   LCD Type 8-Bit MCU
HT49RU80 HOLTEK-HT49RU80_12 Datasheet
376Kb / 54P
   LCD Type 8-Bit MCU
HT49R10A-1 HOLTEK-HT49R10A-1_09 Datasheet
239Kb / 37P
   LCD Type 8-Bit MCU
HT49R50A-1 HOLTEK-HT49R50A-1_09 Datasheet
286Kb / 44P
   LCD Type 8-Bit MCU
HT49R70A-1 HOLTEK-HT49R70A-1_09 Datasheet
280Kb / 44P
   LCD Type 8-Bit MCU
HT49R10A-1 HOLTEK-HT49R10A-1_12 Datasheet
258Kb / 38P
   LCD Type 8-Bit MCU
HT49RU80 HOLTEK-HT49RU80 Datasheet
355Kb / 54P
   LCD Type 8-Bit MCU
HT49R30 HOLTEK-HT49R30 Datasheet
353Kb / 43P
   8-Bit LCD Type MCU
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.NET
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com