參數(shù)資料
型號(hào)： ST72121J4
元件分類(lèi)： 8位微控制器
英文描述： 8-bit Microcontroller with 2/4/8K Bytes In-System Programmable Flash
中文描述： 8位微控制器與2/4/8K字節(jié)在系統(tǒng)可編程閃存
文件頁(yè)數(shù)： 33/93頁(yè)
文件大?。?/td> 915K
代理商： ST72121J4
33/93
ST72E121 ST72T121
5.3 16-BIT TIMER
5.3.1 Introduction
The timer consists of a 16-bit free-running counter
driven by a programmable prescaler.
It may be used for a variety of purposes, including
measuring the pulse lengths of up to two input sig-
nals (input capture) or generating up to two output
waveforms (output compareand PWM).
Pulse lengths and waveform periods can be mod-
ulated from a few microseconds to several milli-
seconds using the timer prescaler and the CPU
clock prescaler.
Some ST7 devices have two on-chip 16-bit timers.
They are completely independent, and do not
share any resources. They are synchronized after
a MCU reset as long as the timer clock frequen-
cies are not modified.
This description covers one or two 16-bit timers. In
ST7 devices with two timers, register names are
prefixed with TA (Timer A) or TB (Timer B).
5.3.2 Main Features
I
Programmable prescaler: f
CPU
divided by 2, 4 or 8.
I
Overflow status flag and maskable interrupt
I
External clock input (must be at least 4 times
slower than the CPU
clock speed) with the choice
of active edge
I
Output compare functions with:
– 2 dedicated 16-bit registers
– 2 dedicated programmable signals
– 2 dedicated status flags
– 1 dedicated maskable interrupt
I
Input capture functions with:
– 2 dedicated 16-bit registers
– 2 dedicated active edge selection signals
– 2 dedicated status flags
– 1 dedicated maskable interrupt
I
Pulse Width Modulation mode (PWM)
I
One Pulse mode
I
5 alternate functions on I/O ports (ICAP1, ICAP2,
OCMP1, OCMP2, EXTCLK)*
The Block Diagram is shown in
Figure 21
.
*Note:
Some timer pins may not be available (not
bonded) in some ST7 devices. Refer to the device
pin out description.
When reading an input signal on a non-bonded
pin, the value will always be ‘1’.
5.3.3 Functional Description
5.3.3.1 Counter
The main block of the Programmable Timer is a
16-bit free running upcounter and its associated
16-bit registers. The 16-bit registers are made up
of two 8-bit registers called high & low.
Counter Register (CR):
– Counter High Register (CHR) is the most sig-
nificant byte (MS Byte).
– Counter Low Register (CLR) is the least sig-
nificant byte (LS Byte).
Alternate Counter Register (ACR)
– Alternate Counter High Register (ACHR) is the
most significant byte (MS Byte).
– Alternate Counter Low Register (ACLR) is the
least significant byte (LS Byte).
These two read-only 16-bit registers contain the
same value but with the difference that reading the
ACLR register does not clear the TOF bit (Timer
overflow flag), located in the Status register (SR).
(See note at the end of paragraph titled 16-bit read
sequence).
Writing in the CLR register or ACLR register resets
the free running counter to the FFFCh value.
Both counters have a reset value of FFFCh (this is
the only value which is reloaded in the 16-bit tim-
er). The reset value of both counters is also
FFFCh in One Pulse mode and PWM mode.
The timer clock depends on the clock control bits
of the CR2 register, as illustrated in
Table 14
. The
value in the counter register repeats every
131072, 262144 or 524288 CPU clock cycles de-
pending on the CC[1:0] bits.
The timer frequency can be f
CPU
/2, f
CPU
/4, f
CPU
/8
or an external frequency.
33
相關(guān)PDF資料
PDF描述
ST72171 8-BIT MCU WITH 8K FLASH. ADC. WDG. SPI. SCI. TIMERS SPGAS (SOFTWARE PROGRAMMABLE GAIN AMPLIFIERS). OP-AMP
ST733C04LFL0 Fuse Holder; Fuse Size/Group:Micro; Mounting Type:PC Board; Body Material:Thermoplastic; Contact Material:Copper Alloy; Contact Plating:Tin; Current Rating:5A; Leaded Process Compatible:Yes; Terminal Type:Push-On
ST733C04LFM0 Fuse Holder; Leaded Process Compatible:Yes; Mounting Type:Panel Mount RoHS Compliant: Yes
ST733C08LFL0 Fuse Holder; Leaded Process Compatible:Yes; Mounting Type:Panel Mount RoHS Compliant: Yes
ST733C08LFM0 Automotive Fuse; Current Rating:3A; Voltage Rating:32V; Fuse Type:Fast Acting; Body Material:Plastic; Fuse Terminals:Blade; Length:15.41mm; Series:297; Voltage Rating:32V; Fuse Size/Group:15.41 x 10.92 x 3.81mm RoHS Compliant: Yes
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ST72124J 制造商:STMICROELECTRONICS 制造商全稱(chēng):STMicroelectronics 功能描述:8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, ADC, 16-BIT TIMERS, SPI, SCI INTERFACES
ST72124J2 制造商:STMICROELECTRONICS 制造商全稱(chēng):STMicroelectronics 功能描述:8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, ADC, 16-BIT TIMERS, SPI, SCI INTERFACES
ST72124J2B 制造商:STMICROELECTRONICS 制造商全稱(chēng):STMicroelectronics 功能描述:8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, ADC, 16-BIT TIMERS, SPI, SCI INTERFACES
ST72124J2B1 制造商:STMICROELECTRONICS 制造商全稱(chēng):STMicroelectronics 功能描述:8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, ADC, 16-BIT TIMERS, SPI, SCI INTERFACES
ST72124J2B1/XXX 制造商:STMICROELECTRONICS 制造商全稱(chēng):STMicroelectronics 功能描述:8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, ADC, 16-BIT TIMERS, SPI, SCI INTERFACES
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(xiě)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(chǎng)商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*