收藏本站
参数资料
型号： ST72F324K4B5
厂商： STMICROELECTRONICS
元件分类： 微控制器/微处理器
英文描述： 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDIP32
封装： 0.400 INCH, ROHS COMPLIANT, SHRINK, PLASTIC, DIP-32
文件页数： 67/164页
文件大小： 2897K
代理商： ST72F324K4B5
ST72324Jx ST72324Kx
159/164
15 KNOWN LIMITATIONS
15.1 ALL DEVICES
15.1.1 External RC option
The External RC clock source option described in
previous datasheet revisions is no longer support-
ed and has been removed from this specification.
15.1.2 CSS Function
The Clock Security System function has been re-
moved from the datasheet.
15.1.3 Safe Connection of OSC1/OSC2 Pins
The OSC1 and/or OSC2 pins must not be left un-
connected otherwise the ST7 main oscillator may
start and, in this configuration, could generate an
fOSC clock frequency in excess of the allowed
maximum (>16MHz.), putting the ST7 in an un-
safe/undefined state. Refer to Section 6.2 on page
24.
15.1.4 Unexpected Reset Fetch
If an interrupt request occurs while a “POP CC” in-
struction is executed, the interrupt controller does
not recognise the source of the interrupt and, by
default, passes the RESET vector address to the
CPU.
Workaround
To solve this issue, a “POP CC” instruction must
always be preceded by a “SIM” instruction.
15.1.5
Clearing
active
interrupts
outside
interrupt routine
When an active interrupt request occurs at the
same time as the related flag is being cleared, an
unwanted reset may occur.
Note: clearing the related interrupt mask will not
generate an unwanted reset
Concurrent interrupt context
The symptom does not occur when the interrupts
are handled normally, i.e.
when:
– The interrupt flag is cleared within its own inter-
rupt routine
– The interrupt flag is cleared within any interrupt
routine
– The interrupt flag is cleared in any part of the
code while this interrupt is disabled
If these conditions are not met, the symptom can
be avoided by implementing the following se-
quence:
Perform SIM and RIM operation before and after
resetting an active interrupt request.
Example:
SIM
reset interrupt flag
RIM
Nested interrupt context:
The symptom does not occur when the interrupts
are handled normally, i.e.
when:
– The interrupt flag is cleared within its own inter-
rupt routine
– The interrupt flag is cleared within any interrupt
routine with higher or identical priority level
– The interrupt flag is cleared in any part of the
code while this interrupt is disabled
If these conditions are not met, the symptom can
be avoided by implementing the following se-
quence:
PUSH CC
SIM
reset interrupt flag
POP CC
15.1.6 External Interrupt Missed
To avoid any risk of generating a parasitic inter-
rupt, the edge detector is automatically disabled
for one clock cycle during an access to either DDR
and OR. Any input signal edge during this period
will not be detected and will not generate an inter-
rupt.
This case can typically occur if the application re-
freshes the port configuration registers at intervals
during runtime.
Workaround
The workaround is based on software checking
the level on the interrupt pin before and after writ-
ing to the PxOR or PxDDR registers. If there is a
level change (depending on the sensitivity pro-
grammed for this pin) the interrupt routine is in-
voked using the call instruction with three extra
PUSH instructions before executing the interrupt
routine (this is to make the call compatible with the
IRET instruction at the end of the interrupt service
routine).
But detection of the level change does ensure that
edge occurs during the critical 1 cycle duration and
the interrupt has been missed. This may lead to
occurrence of same interrupt twice (one hardware
and another with software call).
1
相关PDF资料
PDF描述
ST72F324K6B5 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDIP32
ST72F324K4T6 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP32
ST72F324K2T6 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP32
ST72F324J6T5 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP44
ST72F324K4T3 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP32
相关代理商/技术参数
参数描述
ST72F324K4B6 功能描述:8位微控制器 -MCU 5V RANGE 8B MCU RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72F324K4T6 功能描述:8位微控制器 -MCU Flash 16K SPI/SCI RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72F324K4T6TR 功能描述:8位微控制器 -MCU 5V RANGE 8B MCU RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72F324K4TA 功能描述:8位微控制器 -MCU Flask 16K SPI/SCI RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72F324K4TA/TR 功能描述:8位微控制器 -MCU AUTO 8BIT MICRO RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*