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| 型号： | DS87C520-QCL+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 4/43页 |
| 文件大小： | 0K |
| 描述： | IC MCU EPROM/ROM 33MHZ HS 44PLCC |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 26 |
| 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： | 44-LCC（J 形引线） |
| 包装： | 管件 |
| 产品目录页面： | 703 (CN2011-ZH PDF) |
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DS87C520/DS83C520 EPROM/ROM High-Speed Microcontrollers
12 of 43
When disabled, the 1kB memory area is transparent to the system memory map. Any MOVX directed to
the space between 0000h and FFFFh goes to the expanded bus on Ports 0 and 2. This also is the default
condition. This default allows the DS87C520/DS83C520 to drop into an existing system that uses these
addresses for other hardware and still have full compatibility.
The on-chip data area is software selectable using 2 bits in the Power Management Register at location
C4h. This selection is dynamically programmable. Thus access to the on-chip area becomes transparent to
reach off-chip devices at the same addresses. The control bits are DME1 (PMR.1) and DME0 (PMR.0).
They have the following operation:
Table 2. Data Memory Access Control
DME1
DME0
DATA MEMORY ADDRESS
MEMORY FUNCTION
0
0000h–FFFFh
External data memory (default condition)
0000h–03FFh
Internal SRAM data memory
0
1
0400h–FFFFh
External data memory
1
0
Reserved
0000h–03FFh
Internal SRAM data memory
0400h–FFFBh
Reserved—no external access
FFFCh
Read access to the status of lock bits
1
FFFDh–FFFFh
Reserved—no external access
Notes on the status byte read at FFFCh with DME1, 0 = 1, 1: Bits 2–0 reflect the programmed status of
the security lock bits LB2–LB0. They are individually set to a logic 1 to correspond to a security lock bit
that has been programmed. These status bits allow software to verify that the part has been locked before
running if desired. The bits are read only.
Note: After internal MOVX SRAM has been initialized, changing the DME0/1 bits has no effect on the
contents of the SRAM.
STRETCH MEMORY CYCLE
The DS87C520/DS83C520 allow software to adjust the speed of off-chip data memory access. The
microcontrollers can perform the MOVX in as few as two instruction cycles. The on-chip SRAM uses
this speed and any MOVX instruction directed internally uses two cycles. However, the time can be
stretched for interface to external devices. This allows access to both fast memory and slow memory or
peripherals with no glue logic. Even in high-speed systems, it may not be necessary or desirable to
perform off-chip data memory access at full speed. In addition, there are a variety of memory-mapped
peripherals such as LCDs or UARTs that are slow.
The Stretch MOVX is controlled by the Clock Control Register at SFR location 8Eh as described below.
It allows the user to select a Stretch value between 0 and 7. A Stretch of 0 will result in a two-machine
cycle MOVX. A Stretch of 7 will result in a MOVX of nine machine cycles. Software can dynamically
change this value depending on the particular memory or peripheral.
On reset, the Stretch value will default to a 1, resulting in a three-cycle MOVX for any external access.
Therefore, off-chip RAM access is not at full speed. This is a convenience to existing designs that may
not have fast RAM in place. Internal SRAM access is always at full speed regardless of the Stretch
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相关代理商/技术参数 |
参数描述 |
|---|---|
| DS87C520-QCL/T&R | 制造商:Maxim Integrated Products 功能描述:MICRO,OTP,HI SPD 44PLCC 33MHZ TRL - Tape and Reel 制造商:Maxim Integrated Products 功能描述:IC MCU EPROM/ROM 33MHZ HS 44PLCC |
| DS87C520-QCL/T&R | 功能描述:8位微控制器 -MCU EPROM/ROM High-Speed 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 |
| DS87C520-QCL+ | 功能描述:8位微控制器 -MCU EPROM/ROM High-Speed 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 |
| DS87C520-QCL+T&R | 制造商:Maxim Integrated Products 功能描述:MCU 8BIT CISC 16KB EPROM 5V 44PLCC - Tape and Reel 制造商:Maxim Integrated Products 功能描述:IC MCU EPROM/ROM 33MHZ HS 44PLCC |
| DS87C520-QCL+T&R | 功能描述:8位微控制器 -MCU EPROM/ROM High-Speed 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 |
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