参数资料
型号: R5F21274SDXXXFP
元件分类: 微控制器/微处理器
英文描述: 16-BIT, FLASH, 20 MHz, MICROCONTROLLER, PQFP32
封装: 7 X 7 MM, 0.80 MM PITCH, PLASTIC, LQFP-32
文件页数: 3/52页
文件大小: 620K
代理商: R5F21274SDXXXFP
29
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P [DATASHEET]
8285E–AVR–02/2013
9.3
Default clock source
The device is shipped with CKSEL = “0010”, SUT = “10”, and CKDIV8 programmed. The default clock source set-
ting is the Internal RC Oscillator with longest start-up time and an initial system clock prescaling of 8. This default
setting ensures that all users can make their desired clock source setting using an In-System or Parallel
programmer.
9.4
Calibrated internal RC oscillator
By default, the Internal RC Oscillator provides an approximate 8MHz clock. Though voltage and temperature
dependent, this clock can be very accurately calibrated by the user. See Table 28-11 on page 296 and ”Internal
oscillator speed” on page 331 for more details. The device is shipped with the CKDIV8 Fuse programmed. See
This clock may be selected as the system clock by programming the CKSEL Fuses as shown in Table 9-3. If
selected, it will operate with no external components. During reset, hardware loads the pre-programmed calibration
value into the OSCCAL Register and thereby automatically calibrates the RC Oscillator. The accuracy of this cali-
bration is shown as Factory calibration in Table 28-11 on page 296.
By changing the OSCCAL register from SW, see ”OSCCAL – Oscillator Calibration Register” on page 35, it is pos-
sible to get a higher calibration accuracy than by using the factory calibration. The accuracy of this calibration is
shown as User calibration in Table 28-11 on page 296.
When this Oscillator is used as the chip clock, the Watchdog Oscillator will still be used for the Watchdog Timer
and for the Reset Time-out. For more information on the pre-programmed calibration value, see the section ”Cali-
Notes:
1. The device is shipped with this option selected.
2. The frequency ranges are preliminary values.
3. If 8MHz frequency exceeds the specification of the device (depends on V
CC), the CKDIV8 Fuse can be pro-
grammed in order to divide the internal frequency by 8.
When this Oscillator is selected, start-up times are determined by the SUT Fuses as shown in Table 9-4.
Note:
1. The device is shipped with this option selected
.
Table 9-3.
Internal calibrated RC oscillator operating modes
Frequency Range(2) (MHz)
CKSEL3:0
7.3 - 8.1
0010
Table 9-4.
Start-up times for the internal calibrated RC oscillator clock selection.
Power conditions
Start-up time from power-
down and power-save
Additional delay from
reset (V
CC = 5.0V)
SUT1:0
BOD enabled
6CK
14CK
00
Fast rising power
6CK
14CK + 4.1ms
01
Slowly rising power
6CK
14CK + 65ms(1)
10
Reserved
11
相关PDF资料
PDF描述
R5F21274JFP 16-BIT, FLASH, 20 MHz, MICROCONTROLLER, PQFP32
R5F21264SNXXXFP 16-BIT, FLASH, 20 MHz, MICROCONTROLLER, PQFP32
R5F21265SNXXXFP 16-BIT, FLASH, 20 MHz, MICROCONTROLLER, PQFP32
R5F21272SNFP 16-BIT, FLASH, 20 MHz, MICROCONTROLLER, PQFP32
R5F21264KXXXFP 16-BIT, FLASH, 20 MHz, MICROCONTROLLER, PQFP32
相关代理商/技术参数
参数描述
R5F21274SNFP 制造商:Renesas Electronics Corporation 功能描述:
R5F21274SNFP#U0 制造商:Renesas Electronics Corporation 功能描述:FLASH MEMORY 16 BIT CISC R8C 制造商:Renesas Electronics Corporation 功能描述:IC MCU 16BIT 16KB FLASH 32LQFP
R5F21274SNFP#V0 功能描述:IC R8C/27 MCU FLASH 32LQFP RoHS:是 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:R8C/2x/27 标准包装:96 系列:PIC® 16F 核心处理器:PIC 芯体尺寸:8-位 速度:20MHz 连通性:I²C,SPI 外围设备:欠压检测/复位,POR,PWM,WDT 输入/输出数:11 程序存储器容量:3.5KB(2K x 14) 程序存储器类型:闪存 EEPROM 大小:- RAM 容量:128 x 8 电压 - 电源 (Vcc/Vdd):2.3 V ~ 5.5 V 数据转换器:A/D 8x10b 振荡器型:内部 工作温度:-40°C ~ 125°C 封装/外壳:14-TSSOP(0.173",4.40mm 宽) 包装:管件
R5F21274SNFP#V2 功能描述:MCU 16KB ROM 1KB RAM 32-LQFP RoHS:是 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:R8C/2x/27 标准包装:250 系列:80C 核心处理器:8051 芯体尺寸:8-位 速度:16MHz 连通性:EBI/EMI,I²C,UART/USART 外围设备:POR,PWM,WDT 输入/输出数:40 程序存储器容量:- 程序存储器类型:ROMless EEPROM 大小:- RAM 容量:256 x 8 电压 - 电源 (Vcc/Vdd):4.5 V ~ 5.5 V 数据转换器:A/D 8x10b 振荡器型:内部 工作温度:-40°C ~ 85°C 封装/外壳:68-LCC(J 形引线) 包装:带卷 (TR)
R5F21274SNFP#X6 功能描述:MCU 16KB ROM 1KB RAM 32-LQFP RoHS:是 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:R8C/2x/27 标准包装:300 系列:78K0R/Ix3 核心处理器:78K/0R 芯体尺寸:16-位 速度:40MHz 连通性:3 线 SIO,I²C,LIN,UART/USART 外围设备:DMA,LVD,POR,PWM,WDT 输入/输出数:27 程序存储器容量:16KB(16K x 8) 程序存储器类型:闪存 EEPROM 大小:- RAM 容量:1K x 8 电压 - 电源 (Vcc/Vdd):2.7 V ~ 5.5 V 数据转换器:A/D 8x10b 振荡器型:内部 工作温度:-40°C ~ 85°C 封装/外壳:38-SSOP 包装:托盘