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参数资料
| 型号： | R5F21272SNFP |
| 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： | 10/52页 |
| 文件大小： | 620K |
| 代理商： | R5F21272SNFP |
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35
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P [DATASHEET]
8285E–AVR–02/2013
9.11
Register description
9.11.1
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 varia-
tions 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 28-11 on page 296. The application
software can write this register to change the oscillator frequency. The oscillator can be calibrated to frequencies
as specified in Table 28-11 on page 296. 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 8.8MHz. 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 frequency 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 fre-
quency in that range, and a setting of 0x7F gives the highest frequency in the range.
9.11.2
CLKPR – Clock Prescale Register
Bit 7 – CLKPCE: Clock Prescaler Change Enable
The CLKPCE bit must be written to logic one to enable change of the CLKPS bits. The CLKPCE bit is only updated
when the other bits in CLKPR are simultaneously written to zero. CLKPCE is cleared by hardware four cycles after
it is written or when CLKPS bits are written. Rewriting the CLKPCE bit within this time-out period does neither
extend the time-out period, nor clear the CLKPCE bit.
Bits 3:0 – CLKPS3:0: Clock Prescaler Select Bits 3 - 0
These bits define the division factor between the selected clock source and the internal system clock. These bits
can be written run-time to vary the clock frequency to suit the application requirements. As the divider divides the
master clock input to the MCU, the speed of all synchronous peripherals is reduced when a division factor is used.
The division factors are given in Table 9-14.
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.
The CKDIV8 Fuse determines the initial value of the CLKPS bits. If CKDIV8 is unprogrammed, the CLKPS bits will
be reset to “0000”. If CKDIV8 is programmed, CLKPS bits are reset to “0011”, giving a division factor of 8 at start
up. This feature should be used if the selected clock source has a higher frequency than the maximum frequency
of the device at the present operating conditions. Note that any value can be written to the CLKPS bits regardless
Bit
765
432
10
(0x66)
CAL7
CAL6
CAL5
CAL4
CAL3
CAL2
CAL1
CAL0
OSCCAL
Read/Write
R/W
Initial Value
Device Specific Calibration Value
Bit
7
6
5
4
3210
(0x61)
CLKPCE
–
CLKPS3
CLKPS2
CLKPS1
CLKPS0
CLKPR
Read/Write
R/W
RRR
R/W
Initial Value
0
See Bit Description
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相关代理商/技术参数 |
参数描述 |
|---|---|
| R5F21272SNFP#U0 | 制造商:Renesas Electronics Corporation 功能描述:MCU 16-Bit R8C CISC 8KB Flash 3.3V/5V 32-Pin LQFP Tray 制造商:Renesas Electronics Corporation 功能描述:MCU 16BIT R8C CISC 8KB FLASH 3.3V/5V 32LQFP - Trays 制造商:Renesas Electronics Corporation 功能描述:IC R8C/27 MCU FLASH 32LQFP |
| R5F21272SNFP#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: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) |
| R5F21272SNFP#V2 | 功能描述:MCU 8KB ROM 512B 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) |
| R5F21272SNFP#W4 | 制造商:Renesas Electronics Corporation 功能描述:MCU 3/5V 8+2K PB-FREE 32-LQFP T&R - Tape and Reel |
| R5F21272SNFP#X6 | 功能描述:MCU 8KB ROM 512B 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 |
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