參數(shù)資料
型號(hào)： HT47C20L
廠商： Holtek Semiconductor Inc.
元件分類： 數(shù)學(xué)處理器
英文描述： 8-BIT MICROCONTROLLER
中文描述： 8位微控制器
文件頁(yè)數(shù)： 16/55頁(yè)
文件大?。?/td> 341K
代理商： HT47C20L
HT47C20L
16
January 18, 2000
Oscillator configuration
The HT47C20L provides one 32768Hz crystal
oscillator for real time clock and system clock.
The 32768Hz crystal oscillator still work at halt
mode. The halt mode stop the system clock and
T1 and ignores an external signal to conserve
power. The real time clock comes from 32768Hz
crystal and still works at halt mode.
A 32768Hz crystal across OSC1 and OSC2 is
needed to provide the feedback and phase shift
needed for the oscillator, no other external
components are needed.
Watchdog timer
WDT
The clock source of the WDT (f
s
) is implemented
by a 32768Hz crystal oscillator. The timer is
designed to prevent a software malfunction or
sequence jumping to an unknown location with
unpredictable results. The watchdog timer can
be disabled by mask option. If the watchdog
timer is disabled, all the executions related to
the WDT result in no operation.
The HALT instruction is executed, WDT still
countsandcanwake-upfromhaltmodeduetothe
WDT time-out.
The WDT overflow under normal operation will
initialize chip reset and set the status bit TO.
Whereas in the halt mode, the overflow will ini-
tialize a warm reset only the PC and SP are re-
set to zero. To clear the contents of WDT, three
methods are adopted, external reset (a low level
to RES), software instruction, or a HALT instruc-
tion. The software instructions are of two sets
which includeCLRWDTandtheotherset
WDT1 and CLR WDT2. Of these two types of in-
struction,onlyonecanbeactivedependingonthe
mask option
CLR WDT times selection op-
tion . If the CLR WDT is selected (i.e., CLR
WDT times equal one), any execution of the CLR
WDT instruction will clear the WDT. In case
CLR WDT1 and CLR WDT2 are chosen (i.e.
CLR WDT times equal two), these two instruc-
tions must be executed to clear the WDT; other-
wise, the WDT may reset the chip because of the
time-out.
CLR
The WDT time-out period ranges from
f
s/215
~f
s/216
. The CLR WDT or CLR WDT1
and CLRWDT2 instruction only clear the last
two-stage of the WDT.
Multi-function timer
The HT47C20L provides a multi-function timer
for the WDT, time base and real time clock but
with
different
time-out
multi-function timer consists of a 7-stage di-
vider and an 8-bit prescaler, with the clock
source coming from the 32768Hz. The
multi-function timer also provides a fixed fre-
quency signal (f
s
/8) for the LCD driver circuits,
and a selectable frequency signal (ranges from
f
s
/2
2
to f
s
/2
9
) for buzzer output by mask option.
periods.
The
* + , - . /
'
0 ( 2 7 ( & 1 3
$ ( 1 7
0 (( & 1 3
0( & 1 3
$ 1 ( 1 1
32768Hz crystal
* + , - . / ( $1 (
8
1
:
( 1
<
<
@(
'
( ( ( 6 ( '
,
-
'
'
Watchdog timer
相關(guān)PDF資料
PDF描述
HT47C20 8-BIT MICROCONTROLLER
HT47R20 8 位R-F 型OTP 單片機(jī)
HT48C05 Cost-Effective I/O Type 8-Bit MCU
HT48C06 Cost-Effective I/O Type 8-Bit MCU
HT48C10-1 8-Bit High Performance RISC-like Microcontroller Suitable for Multiple I/O Application(高性能、指令類似RISC的8位微控制器，用于多I/O接口設(shè)備)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
HT47C20L_05 制造商:HOLTEK 制造商全稱:Holtek Semiconductor Inc 功能描述:R-F Type Low Voltage 8-Bit Mask MCU
HT47M50 制造商:NTE Electronics 功能描述:
HT47R10A-1 制造商:HOLTEK 制造商全稱:Holtek Semiconductor Inc 功能描述:R-F Type 8-Bit MCU
HT47R20 制造商:HOLTEK 制造商全稱:Holtek Semiconductor Inc 功能描述:8 位R-F 型OTP 單片機(jī)
HT47R20A-1 制造商:HOLTEK 制造商全稱:Holtek Semiconductor Inc 功能描述:R-F Type 8-Bit MCU
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*