- 您现在的位置：买卖IC网 > PDF目录190063 > PIC17C44 Low Power 5V RS232 Dual Driver/Receiver with 0.1?μF Capacitors; Package: SO; No of Pins: 16; Temperature Range: -40?°C to 85?°C PDF资料下载
参数资料
| 型号： | PIC17C44 |
| 元件分类： | 外设及接口 |
| 英文描述： | Low Power 5V RS232 Dual Driver/Receiver with 0.1?μF Capacitors; Package: SO; No of Pins: 16; Temperature Range: -40?°C to 85?°C |
| 中文描述： | 电可擦除可编程逻辑器件 |
| 文件页数： | 65/71页 |
| 文件大小： | 1173K |
| 代理商： | PIC17C44 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页当前第65页第66页第67页第68页第69页第70页第71页
PIC17C4X
DS30412C-page 68
1996 Microchip Technology Inc.
11.1
Timer0 Operation
When the T0CS (T0STA<5>) bit is set, TMR0 incre-
ments on the internal clock. When T0CS is clear, TMR0
increments on the external clock (RA1/T0CKI pin). The
external clock edge can be congured in software.
When the T0SE (T0STA<6>) bit is set, the timer will
increment on the rising edge of the RA1/T0CKI pin.
When T0SE is clear, the timer will increment on the fall-
ing edge of the RA1/T0CKI pin. The prescaler can be
programmed to introduce a prescale of 1:1 to 1:256.
The timer increments from 0000h to FFFFh and rolls
over to 0000h. On overow, the TMR0 Interrupt Flag bit
(T0IF) is set. The TMR0 interrupt can be masked by
clearing the corresponding TMR0 Interrupt Enable bit
(T0IE). The TMR0 Interrupt Flag bit (T0IF) is automati-
cally cleared when vectoring to the TMR0 interrupt vec-
tor.
11.2
Using Timer0 with External Clock
When the external clock input is used for Timer0, it is
synchronized
with
the
internal
phase
clocks.
Figure 11-3 shows the synchronization of the external
clock. This synchronization is done after the prescaler.
The output of the prescaler (PSOUT) is sampled twice
in every instruction cycle to detect a rising or a falling
edge. The timing requirements for the external clock
are detailed in the electrical specication section for the
desired device.
11.2.1
DELAY FROM EXTERNAL CLOCK EDGE
Since the prescaler output is synchronized with the
internal clocks, there is a small delay from the time the
external clock edge occurs to the time TMR0 is actually
incremented. Figure 11-3 shows that this delay is
between 3TOSC and 7TOSC. Thus, for example, mea-
suring the interval between two edges (e.g. period) will
be accurate within
±4TOSC (±121 ns @ 33 MHz).
FIGURE 11-2: TIMER0 MODULE BLOCK DIAGRAM
FIGURE 11-3: TMR0 TIMING WITH EXTERNAL CLOCK (INCREMENT ON FALLING EDGE)
RA1/T0CKI
Synchronization
Prescaler
(8 stage
async ripple
counter)
T0SE
(T0STA<6>)
Fosc/4
T0CS
(T0STA<5>)
PS3:PS0
(T0STA<4:1>)
Q2
Q4
0
1
TMR0H<8> TMR0L<8>
Interrupt on overow
sets T0IF
(INTSTA<5>)
4
PSOUT
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Prescaler
output
(PSOUT)
Sampled
Prescaler
output
Increment
TMR0
T0
T0 + 1
T0 + 2
(note 3)
(note 2)
Note 1: The delay from the T0CKI edge to the TMR0 increment is 3Tosc to 7Tosc.
2:
↑ = PSOUT is sampled here.
3: The PSOUT high time is too short and is missed by the sampling circuit.
(note 1)
相关PDF资料 |
PDF描述 |
|---|---|
| PIC17C766T-33E/L | 8-BIT, OTPROM, 33 MHz, RISC MICROCONTROLLER, PQCC84 |
| PIC18C242-I/SO | 8-BIT, OTPROM, 40 MHz, RISC MICROCONTROLLER, PDSO28 |
| PIC18C442-E/L | 8-BIT, OTPROM, 40 MHz, RISC MICROCONTROLLER, PQCC44 |
| PIC18F2515 | PIC18FX515/X610 Product Brief |
| PIC18F2539 | PIC18F2539 Motor Control Evaluation Kit |
相关代理商/技术参数 |
参数描述 |
|---|---|
| PIC17C44/JW | 功能描述:8位微控制器 -MCU 16KB 454 RAM 33 I/O RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
| PIC17C44-16/L | 功能描述:8位微控制器 -MCU 16KB 454 RAM 33 I/O RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
| PIC17C44-16/P | 功能描述:8位微控制器 -MCU 16KB 454 RAM 33 I/O RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
| PIC17C44-16/P | 制造商:Microchip Technology Inc 功能描述:IC 8-BIT CMOS MCU OTP ((NS)) |
| PIC17C44-16/PQ | 功能描述:8位微控制器 -MCU 16KB 454 RAM 33 I/O RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
发布紧急采购，3分钟左右您将得到回复。