參數(shù)資料
型號: HMS81C20XXA
廠商: Electronic Theatre Controls, Inc.
英文描述: CMOS Single-Chip 8-Bit Microcontroller with A/D Converter & VFD Driver
中文描述: CMOS單芯片8位微控制器與A / D轉換器
文件頁數(shù): 44/107頁
文件大?。?/td> 1482K
代理商: HMS81C20XXA
HMS81C2012A/2020A
40
SEP. 2004 Ver 2.00
10. BASIC INTERVAL TIMER
The HMS81C20xxA has one 8-bit Basic Interval Timer
that is free-run, can not stop. Block diagram is shown in
Figure 10-1. In addition, the Basic Interval Timer gener-
ates the time base for watchdog timer counting. It also pro-
vides a Basic interval timer interrupt (BITIF).
The 8-bit Basic interval timer register (BITR) is increased
every internal count pulse which is divided by prescaler.
Since prescaler has divided ratio by 8 to 1024, the count
rate is 1/8 to 1/1024 of the oscillator frequency. As the
count overflows from FF
H
to 00
H
, this overflow causes to
generate the Basic interval timer interrupt. The BITIF is in-
terrupt request flag of Basic interval timer. The Basic In-
terval Timer is controlled by the clock control register
(CKCTLR) shown in Figure 10-2.
When write "1" to bit BTCL of CKCTLR, BITR register is
cleared to "0" and restart to count-up. The bit BTCL be-
comes "0" after one machine cycle by hardware.
If the STOP instruction executed after writing "1" to bit
WAKEUP of CKCTLR, it goes into the wake-up timer
mode. In this mode, all of the block is halted except the os-
cillator, prescaler (only fXIN
÷
2048) and Timer0.
If the STOP instruction executed after writing "1" to bit
RCWDT of CKCTLR, it goes into the internal RC oscillat-
ed watchdog timer mode. In this mode, all of the block is
halted except the internal RC oscillator, Basic Interval
Timer and Watchdog Timer. More detail informations are
explained in Power Saving Function. The bit WDTON de-
cides Watchdog Timer or the normal 7-bit timer.
Source clock can be selected by lower 3 bits of CKCTLR.
BITR and CKCTLR are located at same address, and ad-
dress 0EC
H
is read as a BITR, and written to CKCTLR.
Figure 10-1 Block Diagram of Basic Interval Timer
MUX
Basic Interval
Timer Interrupt
BITR
Select Input clock 3
Basic Interval Timer
clock control register
source
clock
8-bit up-counter
BTS[2:0]
BTCL
÷
1024
÷
512
÷
256
÷
128
÷
64
÷
32
÷
16
÷
8
To Watchdog timer (WDTCK)
CKCTLR
clear
overflow
Internal bus line
[0EC
H
]
[0EC
H
]
BITIF
Read
X
IN
PIN
P
Internal RC OSC
RCWDT
1
0
WAKEUP
STOP
相關PDF資料
PDF描述
HMS81C20XXA-HK CMOS Single-Chip 8-Bit Microcontroller with A/D Converter & VFD Driver
HN2716 2048-word x 8bit Erasable and Electrically Programmable Only Memory
HN27512 512K (64K X 8 BIT ) UV AND OTP EPROM
HN27512P-25 512K (64K X 8 BIT ) UV AND OTP EPROM
HN27512P-30 512K (64K X 8 BIT ) UV AND OTP EPROM
相關代理商/技術參數(shù)
參數(shù)描述
HMS81C20XXA-HK 制造商:未知廠家 制造商全稱:未知廠家 功能描述:CMOS Single-Chip 8-Bit Microcontroller with A/D Converter & VFD Driver
HMS81C2112A 制造商:未知廠家 制造商全稱:未知廠家 功能描述:[VFD MCU: High Voltage IO/ADC/HS PWM/SCI]
HMS81C2120A 制造商:未知廠家 制造商全稱:未知廠家 功能描述:[VFD MCU: High Voltage IO/ADC/HS PWM/SCI]
HMS81C4260 制造商:HYNIX 制造商全稱:Hynix Semiconductor 功能描述:HYNIX SEMICONDUCTOR INC. 8-BIT SINGLE-CHIP MICROCONTROLLERS
HMS81C4308 制造商:未知廠家 制造商全稱:未知廠家 功能描述:[TV : OSD/ I?C]