参数资料
型号: ST10F269Z2Q3
厂商: STMICROELECTRONICS
元件分类: 微控制器/微处理器
英文描述: 16-BIT, FLASH, 40 MHz, MICROCONTROLLER, PQFP144
封装: 28 X 28 MM, PLASTIC, QFP-144
文件页数: 44/160页
文件大小: 1541K
代理商: ST10F269Z2Q3
ST10F269
138/160
21.4.4 - Prescaler Operation
When pins P0.15-13 (P0H.7-5) equal ’001’ during
reset, the CPU clock is derived from the internal
oscillator (input clock signal) by a 2:1 prescaler.
The frequency of fCPU is half the frequency of
fXTAL and the high and low time of fCPU (i.e. the
duration of an individual TCL) is defined by the
period of the input clock fXTAL.
The timings listed in the AC Characteristics that
refer to TCL therefore can be calculated using the
period of fXTAL for any TCL.
Note that if the bit OWDDIS in SYSCON register
is cleared, the PLL runs on its free-running
frequency and delivers the clock signal for the
Oscillator Watchdog. If bit OWDDIS is set, then
the PLL is switched off.
21.4.5 - Direct Drive
When pins P0.15-13 (P0H.7-5) equal ’011’ during
reset the on-chip phase locked loop is disabled
and the CPU clock is directly driven from the
internal oscillator with the input clock signal.
The
frequency
of fCPU directly follows the
frequency of fXTAL so the high and low time of fCPU
(i.e. the duration of an individual TCL) is defined
by the duty cycle of the input clock fXTAL.
Therefore, the timings given in this chapter refer to
the minimum TCL. This minimum value can be
calculated by the following formula:
For two consecutive TCLs, the deviation caused
by the duty cycle of fXTAL is compensated, so the
duration of 2TCL is always 1/fXTAL.
The minimum value TCLmin has to be used only
once for timings that require an odd number of
TCLs (1,3,...). Timings that require an even
number of TCLs (2,4,...) may use the formula:
Note:
The address float timings in Multiplexed
bus mode (t11 and t45) use the maximum
duration of TCL (TCLmax = 1/fXTAL x
DCmax) instead of TCLmin.
If the bit OWDDIS in SYSCON register is
cleared, the PLL runs on its free-running
frequency and delivers the clock signal for
the Oscillator Watchdog. If bit OWDDIS is
set, then the PLL is switched off.
21.4.6 - Oscillator Watchdog (OWD)
An on-chip watchdog oscillator is implemented in
the ST10F269. This feature is used for safety
operation with external crystal oscillator (using
direct drive mode with or without prescaler). This
watchdog oscillator operates as following :
The
reset default configuration
enables the
watchdog oscillator. It can be disabled by setting
the OWDDIS (bit 4) of SYSCON register.
When the OWD is enabled, the PLL runs at its
free-running frequency, and it increments the
watchdog
counter.
The
PLL
free-running
frequency is between 2 and 10MHz. On each
transition of external clock, the watchdog counter
is cleared. If an external clock failure occurs, then
the watchdog counter overflows (after 16 PLL
clock cycles).
The CPU clock signal will be switched to the PLL
free-running clock signal, and the oscillator
watchdog Interrupt Request (XP3INT) is flagged.
The CPU clock will not switch back to the external
clock even if a valid external clock exits on XTAL1
pin. Only a hardware reset can switch the CPU
clock source back to direct clock input.
When the OWD is disabled, the CPU clock is
always external oscillator clock and the PLL is
switched off to decrease consumption supply
current.
21.4.7 - Phase Locked Loop
For all other combinations of pins P0.15-13
(P0H.7-5) during reset the on-chip phase locked
loop is enabled and it provides the CPU clock (see
Table 34). The PLL multiplies the input frequency
by the factor F which is selected via the
combination of pins P0.15-13 (fCPU = fXTAL x F).
With every F’th transition of fXTAL the PLL circuit
synchronizes the CPU clock to the input clock.
This synchronization is done smoothly, so the
CPU clock frequency does not change abruptly.
Due to this adaptation to the input clock the
frequency of fCPU is constantly adjusted so it is
locked to fXTAL. The slight variation causes a jitter
of fCPU which also effects the duration of
individual TCLs.
The timings listed in the AC Characteristics that
refer to TCLs therefore must be calculated using
the minimum TCL that is possible under the
respective circumstances.
TCL
min
1f
XT ALl
xlDC
min
=
DC
duty cycle
=
2T CL
1 f
XT AL
=
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相关代理商/技术参数
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ST10F269Z2Q6/TR 功能描述:16位微控制器 - MCU 16B MCU 256K Byte and 12K Byte RAM RoHS:否 制造商:Texas Instruments 核心:RISC 处理器系列:MSP430FR572x 数据总线宽度:16 bit 最大时钟频率:24 MHz 程序存储器大小:8 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:VQFN-40 安装风格:SMD/SMT
ST10F269Z2QX 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:16-BIT MCU WITH MAC UNIT, 256K BYTE FLASH MEMORY AND 12K BYTE RAM
ST10F269Z2T3 功能描述:16位微控制器 - MCU ST10F272 16B MCU RoHS:否 制造商:Texas Instruments 核心:RISC 处理器系列:MSP430FR572x 数据总线宽度:16 bit 最大时钟频率:24 MHz 程序存储器大小:8 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:VQFN-40 安装风格:SMD/SMT
ST10F269Z2T6 功能描述:16位微控制器 - MCU ST10F272 16B MCU RoHS:否 制造商:Texas Instruments 核心:RISC 处理器系列:MSP430FR572x 数据总线宽度:16 bit 最大时钟频率:24 MHz 程序存储器大小:8 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:VQFN-40 安装风格:SMD/SMT