参数资料
型号: R80C52EXXX-20:R
厂商: TEMIC SEMICONDUCTORS
元件分类: 微控制器/微处理器
英文描述: 8-BIT, MROM, 20 MHz, MICROCONTROLLER, CQCC44
文件页数: 17/91页
文件大小: 19688K
29
7707F–AVR–11/10
AT90USB82/162
6.2.5
Clock Status Register – CLKSTA
Bit 7-2 - Reserved bits
These bits are reserved and will always read as zero.
Bit 1 – RCON: RC Oscillator On
This bit is set by hardware to one if the RC Oscillator is running.
This bit is set by hardware to zero if the RC Oscillator is stoped.
Bit 0 – EXTON: External Oscillator / Low Power Oscillator On
This bit is set by hardware to one if the External Oscillator / Low Power Oscillator is running.
This bit is set by hardware to zero if the External Oscillator / Low Power Oscillator is stoped.
6.3
Clock Sources
The device has the following clock source options, selectable by Flash Fuse bits as shown
below. The clock from the selected source is input to the AVR clock generator, and routed to the
appropriate modules.
Note:
1. For all fuses “1” means unprogrammed while “0” means programmed.
6.3.1
Default Clock Source
The device is shipped with low power crystal oscillator and with the fuse CKDIV8 programmed.
The startup time is set to maximum and time-out period enabled. (CKSEL = "1110", SUT = "01",
CKDIV8 = "0").
6.3.2
Clock Startup Sequence
Any clock source needs a sufficient V
CC to start oscillating and a minimum number of oscillating
cycles before it can be considered stable.
To ensure sufficient V
CC, the device issues an internal reset with a time-out delay (tTOUT) after
the device reset is released by all other reset sources. “On-chip Debug System” on page 45
describes the start conditions for the internal reset. The delay (t
TOUT) is timed from the Watchdog
Oscillator and the number of cycles in the delay is set by the SUTx and CKSELx fuse bits. The
selectable delays are shown in Table 6-2. The frequency of the Watchdog Oscillator is voltage
Bit
7
6
543
2
1
0
-
RCON
EXTON
CLKSTA
Read/Write
R
Initial Value
0
See Bit Description
Table 6-1.
Device Clocking Options Select
Device Clocking Option
CKSEL3..0
Low Power Crystal Oscillator
1111 - 1000
Reserved
0111 - 0110
Reserved
0101 - 0100
Reserved
0011
Calibrated Internal RC Oscillator
0010
External Clock
0000
Reserved
0001
相关PDF资料
PDF描述
R80C52EXXX-20SHXXX 8-BIT, MROM, 20 MHz, MICROCONTROLLER, CQCC44
R80C52EXXX-25:RD 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CQCC44
R80C52EXXX-25 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CQCC44
R80C52EXXX-30SHXXX:RD 8-BIT, MROM, 30 MHz, MICROCONTROLLER, CQCC44
R80C52EXXX-30 8-BIT, MROM, 30 MHz, MICROCONTROLLER, CQCC44
相关代理商/技术参数
参数描述
R80ES11WES 制造商:UNBRANDED 功能描述:LAMP ENERGY SAVING R80 11W ES
R80M 制造商:Omron Corporation 功能描述:
R80P 制造商:Orion Fans 功能描述:Filter Kit; Retainer only; ABS UL94V-0; Fits 80mm Fan; 83.6mm W; 9.8mm D
R80X5200CK 制造商:Samsung Semiconductor 功能描述:100 Pack 52x80 Minute CD-R Media
R8-10 制造商:JST Manufacturing 功能描述:8AWG 29.8mm 15mm 制造商:JST Manufacturing 功能描述:Terminal,R8-10