收藏本站
Device Overview S12XS Family
The clock generated by the PLL or oscillator provides the main system clock frequencies core clock and
bus clock. As shown in Figure 1-6 , these system clocks are used throughout the MCU to drive the core,
the memories, and the peripherals.
The program Flash memory is supplied by the bus clock and the oscillator clock. The oscillator clock is
used as a time base to derive the program and erase times for the NVMs.
The CAN modules may be con?gured to have their clock sources derived either from the bus clock or
directly from the oscillator clock. This allows the user to select its clock based on the required jitter
performance.
In order to ensure the presence of the clock the MCU includes an on-chip clock monitor connected to the
output of the oscillator. The clock monitor can be con?gured to invoke the PLL self-clocking mode or to
generate a system reset if it is allowed to time out as a result of no oscillator clock being present.
In addition to the clock monitor, the MCU also provides a clock quality checker which performs a more
accurate check of the clock. The clock quality checker counts a predetermined number of clock edges
within a de?ned time window to insure that the clock is running. The checker can be invoked following
speci?c events such as on wake-up or clock monitor failure.
1.4
Modes of Operation
The MCU can operate in different modes. These are described in 1.4.1 Chip Con?guration Summary .
The MCU can operate in different power modes to facilitate power saving when full system performance
is not required. These are described in 1.4.2 Power Modes .
Some modules feature a software programmable option to freeze the module status whilst the background
debug module is active to facilitate debugging. This is described in 1.4.3 Freeze Mode .
1.4.1
Chip Con?guration Summary
The different modes and the security state of the MCU affect the debug features (enabled or disabled).
The operating mode out of reset is determined by the state of the MODC signal during reset (see Table 1-
8 ). The MODC bit in the MODE register shows the current operating mode and provides limited mode
switching during operation. The state of the MODC signal is latched into this bit on the rising edge of
RESET.
Table 1-8. Chip Modes
Chip Modes
Normal single chip
Special single chip
MODC
1
0
1.4.1.1
Normal Single-Chip Mode
This mode is intended for normal device operation. The opcode from the on-chip memory is being
executed after reset (requires the reset vector to be programmed correctly). The processor program is
executed from internal memory.
S12XS Family Reference Manual, Rev. 1.13
Freescale Semiconductor
49
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

*
*
*
相关PDF资料
LFXP10E-L-EV BOARD EVAL LATTICEXP10E STD
LH28F008SCHT-TE IC FLASH 8MBIT 85NS 40TSOP
LH28F160S3HNS-TV IC FLASH 16MBIT 100NS 56SSOP
LH28F160S5HNS-S1 IC FLASH 16MBIT 70NS 56SSOP
LH28F320S3HNS-ZM IC FLASH 32MBIT 110NS 56SSOP
LH28F320SKTD-ZR IC FLASH 32MBIT 70NS 48TSOP
LHF00L28 IC FLASH 16MBIT 70NS 48TSOP
LPM409 CHASSIS STNRD 4SLOT CHASSIS W/INPUT LEAD
相关代理商/技术参数
LFDP25N0005AB 制造商:Murata Manufacturing Co Ltd 功能描述:
LFDP25N0013AB 制造商:Murata Manufacturing Co Ltd 功能描述:
LFDS0030X 功能描述:控制开关 Disconnect Switches Fusible/Non-fusible RoHS:否 制造商:Omron Industrial 控制类型:Emergency Stop 触点额定值:5 A at 125 VAC 触点形式:1 Form B (SPST-NC) 电压额定值: 电流额定值: 执行器:Pushbutton 照明:N 安装风格:
LFDS0040X 功能描述:控制开关 40A Disconnect Switch RoHS:否 制造商:Omron Industrial 控制类型:Emergency Stop 触点额定值:5 A at 125 VAC 触点形式:1 Form B (SPST-NC) 电压额定值: 电流额定值: 执行器:Pushbutton 照明:N 安装风格:
LFDS0060X 功能描述:控制开关 60A Disconnect Switch RoHS:否 制造商:Omron Industrial 控制类型:Emergency Stop 触点额定值:5 A at 125 VAC 触点形式:1 Form B (SPST-NC) 电压额定值: 电流额定值: 执行器:Pushbutton 照明:N 安装风格:
LFDS040 制造商:LITTELFUSE 制造商全称:Littelfuse 功能描述:Disconnect Switches
LFDS060 制造商:LITTELFUSE 制造商全称:Littelfuse 功能描述:Disconnect Switches
LFDW 制造商:LINER 制造商全称:Linear Technology 功能描述:1A Micropower Step-Down