参数资料
型号: DS87C530-ECL
厂商: Maxim Integrated Products
文件页数: 10/45页
文件大小: 0K
描述: IC MCU EPR/ROM W/RTC 33MZ 52TQFP
标准包装: 96
系列: 87C
核心处理器: 8051
芯体尺寸: 8-位
速度: 33MHz
连通性: EBI/EMI,SIO,UART/USART
外围设备: 电源故障复位,WDT
输入/输出数: 32
程序存储器容量: 16KB(16K x 8)
程序存储器类型: OTP
RAM 容量: 1K x 8
电压 - 电源 (Vcc/Vdd): 4.5 V ~ 5.5 V
振荡器型: 外部
工作温度: 0°C ~ 70°C
封装/外壳: 52-TQFP
包装: 托盘
DS87C530/DS83C530 EPROM/ROM Microcontrollers with Real-Time Clock
18 of 45
CRYSTAL-LESS PMM
A major component of power consumption in PMM is the crystal amplifier circuit. The
DS87C530/DS83C530 allow the user to switch CPU operation to an internal ring oscillator and turn off
the crystal amplifier. The CPU would then have a clock source of approximately 2MHz to 4MHz, divided
by either 4, 64, or 1024. The ring is not accurate, so software cannot perform precision timing. However,
this mode allows an additional saving of between 0.5mA and 6.0mA, depending on the actual crystal
frequency. While this saving is of little use when running at 4 clocks per instruction cycle, it makes a
major contribution when running in PMM1 or PMM2.
PMM OPERATION
Software invokes the PMM by setting the appropriate bits in the SFR area. The basic choices are divider
speed and clock source. There are three speeds (4, 64, and 1024) and two clock sources (crystal, ring).
Both the decisions and the controls are separate. Software will typically select the clock speed first. Then,
it will perform the switch to ring operation if desired. Lastly, software can disable the crystal amplifier if
desired.
There are two ways of exiting PMM. Software can remove the condition by reversing the procedure that
invoked PMM or hardware can (optionally) remove it. To resume operation at a divide-by-4 rate under
software control, simply select 4 clocks per cycle, and then crystal-based operation if relevant. When
disabling the crystal as the time base in favor of the ring oscillator, there are timing restrictions associated
with restarting the crystal operation. Details are described below.
There are three registers containing bits that are concerned with PMM functions. They are Power
Management Register (PMR; C4h), Status (STATUS; C5h), and External Interrupt Flag (EXIF; 91h)
Clock Divider
Software can select the instruction cycle rate by selecting bits CD1 (PMR.7) and CD0 (PMR.6) as
follows:
CD1
CD0
CYCLE RATE
0
Reserved
0
1
4 clocks (default)
1
0
64 clocks
1
1024 clocks
The selection of instruction cycle rate will take effect after a delay of one instruction cycle. Note that the
clock divider choice applies to all functions including timers. Since baud rates are altered, it will be
difficult to conduct serial communication while in PMM. There are minor restrictions on accessing the
clock selection bits. The processor must be running in a 4-clock state to select either 64 (PMM1) or 1024
(PMM2) clocks. This means software cannot go directly from PMM1 to PMM2 or visa versa. It must
return to a 4-clock rate first.
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DS87C530-ECL+ 功能描述:8位微控制器 -MCU EPROM MCU w/RTC 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
DS87C530-ENL 功能描述:8位微控制器 -MCU EPROM MCU w/RTC 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
DS87C530-ENL+ 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:EPROM/ROM Microcontrollers with Real-Time Clock
DS87C530-KCL 功能描述:8位微控制器 -MCU EPROM MCU w/RTC 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