- 您现在的位置：买卖IC网 > PDF目录3764 > SC16C654BIA68,518 (NXP Semiconductors)IC UART QUAD W/FIFO 68-PLCC PDF资料下载
参数资料
| 型号： | SC16C654BIA68,518 |
| 厂商： | NXP Semiconductors |
| 文件页数： | 33/58页 |
| 文件大小： | 0K |
| 描述： | IC UART QUAD W/FIFO 68-PLCC |
| 产品培训模块： | Stand-Alone UARTs |
| 标准包装： | 1 |
| 特点： | 故障启动位检测 |
| 通道数： | 4，QUART |
| FIFO's： | 64 字节 |
| 电源电压： | 2.5V，3.3V，5V |
| 带自动流量控制功能： | 是 |
| 带IrDA 编码器/解码器： | 是 |
| 带故障启动位检测功能： | 是 |
| 带调制解调器控制功能： | 是 |
| 带CMOS： | 是 |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 68-LCC（J 形引线） |
| 供应商设备封装： | 68-PLCC |
| 包装： | 剪切带 (CT) |
| 产品目录页面： | 828 (CN2011-ZH PDF) |
| 其它名称： | 568-2047 568-2047-ND |
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页当前第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
39
7674F–AVR–09/09
ATmega164P/324P/644P
When switching between prescaler settings, the System Clock Prescaler ensures that no
glitches occurs in the clock system. It also ensures that no intermediate frequency is higher than
neither the clock frequency corresponding to the previous setting, nor the clock frequency corre-
sponding to the new setting.
The ripple counter that implements the prescaler runs at the frequency of the undivided clock,
which may be faster than the CPU's clock frequency. Hence, it is not possible to determine the
state of the prescaler - even if it were readable, and the exact time it takes to switch from one
clock division to the other cannot be exactly predicted. From the time the CLKPS values are writ-
ten, it takes between T1 + T2 and T1 + 2 * T2 before the new clock frequency is active. In this
interval, 2 active clock edges are produced. Here, T1 is the previous clock period, and T2 is the
period corresponding to the new prescaler setting.
To avoid unintentional changes of clock frequency, a special write procedure must be followed
to change the CLKPS bits:
1.
Write the Clock Prescaler Change Enable (CLKPCE) bit to one and all other bits in
CLKPR to zero.
2.
Within four cycles, write the desired value to CLKPS while writing a zero to CLKPCE.
Interrupts must be disabled when changing prescaler setting to make sure the write procedure is
not interrupted.
7.12
Register Description
7.12.1
OSCCAL – Oscillator Calibration Register
Bits 7:0 – CAL7:0: Oscillator Calibration Value
The Oscillator Calibration Register is used to trim the Calibrated Internal RC Oscillator to
remove process variations from the oscillator frequency. A pre-programmed calibration value is
automatically written to this register during chip reset, giving the Factory calibrated frequency as
specified in Table 26-2 on page 331. The application software can write this register to change
the oscillator frequency. The oscillator can be calibrated to frequencies as specified in Table
26-2 on page 331. Calibration outside that range is not guaranteed.
Note that this oscillator is used to time EEPROM and Flash write accesses, and these write
times will be affected accordingly. If the EEPROM or Flash are written, do not calibrate to more
than 8.8 MHz. Otherwise, the EEPROM or Flash write may fail.
The CAL7 bit determines the range of operation for the oscillator. Setting this bit to 0 gives the
lowest frequency range, setting this bit to 1 gives the highest frequency range. The two fre-
quency ranges are overlapping, in other words a setting of OSCCAL = 0x7F gives a higher
frequency than OSCCAL = 0x80.
The CAL6..0 bits are used to tune the frequency within the selected range. A setting of 0x00
gives the lowest frequency in that range, and a setting of 0x7F gives the highest frequency in the
range.
Bit
7
6
543210
CAL7
CAL6
CAL5
CAL4
CAL3
CAL2
CAL1
CAL0
OSCCAL
Read/Write
R/W
Initial Value
Device Specific Calibration Value
相关PDF资料 |
PDF描述 |
|---|---|
| SCC2681AC1N28,112 | IC UART 28-DIP |
| SC26C92C1B,551 | IC UART DUAL W/FIFO 44PQFP |
| SCC2692AC1A44,512 | IC UART DUAL 44-PLCC |
| SCC2692AC1N40,602 | IC UART DUAL 40-DIP |
| SCC2681AC1A44,529 | IC DUART 44-PLCC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| SC16C654BIA68-S | 功能描述:UART 接口集成电路 16CB 2.5V-5V 4CH UART 64B FIFO RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel |
| SC16C654BIA68-T | 功能描述:UART 接口集成电路 16CB 2.5V-5V 4CH UART 64B FIFO RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel |
| SC16C654BIB64 | 功能描述:UART 接口集成电路 16CB 2.5V-5V 4CH UART 64B FIFO RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel |
| SC16C654BIB64,128 | 功能描述:UART 接口集成电路 16CB 2.5V-5V 4CH RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel |
| SC16C654BIB64,151 | 功能描述:UART 接口集成电路 16CB 2.5V-5V 4CH RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel |
发布紧急采购，3分钟左右您将得到回复。