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参数资料
| 型号： | COP8SGA040N9 |
| 厂商： | National Semiconductor Corporation |
| 英文描述： | 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART |
| 中文描述： | 8位的CMOS基于ROM和OTP微控制器具有8K到32K的内存，2个比较器和USART |
| 文件页数： | 3/62页 |
| 文件大小： | 913K |
| 代理商： | COP8SGA040N9 |
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1.0 Device Description
1.1 ARCHITECTURE
The COP8 family is based on a modified Harvard architec-
ture, which allows data tables to be accessed directly from
program memory. This is very important with modern
microcontroller-based applications, since program memory
is usually ROM or EPROM, while data memory is usually
RAM. Consequently data tables need to be contained in
non-volatile memory, so they are not lost when the micro-
controller is powered down. In a modified Harvard architec-
ture, instruction fetch and memory data transfers can be
overlapped with a two stage pipeline, which allows the next
instruction to be fetched from program memory while the
current instruction is being executed using data memory.
This is not possible with a Von Neumann single-address bus
architecture.
The COP8 family supports a software stack scheme that
allows the user to incorporate many subroutine calls. This
capability is important when using High Level Languages.
With a hardware stack, the user is limited to a small fixed
number of stack levels.
1.2 INSTRUCTION SET
In today’s 8-bit microcontroller application arena cost/
performance, flexibility and time to market are several of the
key issues that system designers face in attempting to build
well-engineered products that compete in the marketplace.
Many of these issues can be addressed through the manner
in which a microcontroller’s instruction set handles process-
ing tasks. And that’s why COP8 family offers a unique and
code-efficient instruction set—one that provides the flexibil-
ity, functionality, reduced costs and faster time to market that
today’s microcontroller based products require.
Code efficiency is important because it enables designers to
pack more on-chip functionality into less program memory
space. Selecting a microcontroller with less program
memory size translates into lower system costs, and the
added security of knowing that more code can be packed
into the available program memory space.
1.2.1 Key Instruction Set Features
The COP8 family incorporates a unique combination of in-
struction set features, which provide designers with optimum
code efficiency and program memory utilization.
Single Byte/Single Cycle Code Execution
The efficiency is due to the fact that the majority of instruc-
tions are of the single byte variety, resulting in minimum
program space. Because compact code does not occupy a
substantial amount of program memory space, designers
can integrate additional features and functionality into the
microcontroller program memory space. Also, the majority
instructions executed by the device are single cycle, result-
ing in minimum program execution time. In fact, 77% of the
instructions are single byte single cycle, providing greater
code and I/O efficiency, and faster code execution.
1.2.2 Many Single-Byte, Multifunction Instructions
The COP8 instruction set utilizes many single-byte, multi-
function instructions. This enables a single instruction to
accomplish multiple functions, such as DRSZ, DCOR, JID,
LD (Load) and X (Exchange) instructions with post-
incrementing and post-decrementing, to name just a few
examples. In many cases, the instruction set can simulta-
neously execute as many as three functions with the same
single-byte instruction.
JID:
(Jump Indirect); Single byte instruction; decodes exter-
nal events and jumps to corresponding service routines
(analogous to “DO CASE” statements in higher level lan-
guages).
LAID:
(Load Accumulator-Indirect); Single byte look up table
instruction provides efficient data path from the program
memory to the CPU. This instruction can be used for table
lookup and to read the entire program memory for checksum
calculations.
RETSK:
(Return Skip); Single byte instruction allows return
from subroutine and skips next instruction. Decision to
branch can be made in the subroutine itself, saving code.
AUTOINC/DEC:
(Auto-Increment/Auto-Decrement); These
instructions use the two memory pointers B and X to effi-
ciently process a block of data (analogous to “FOR NEXT” in
higher level languages).
1.2.3 Bit-Level Control
Bit-level control over many of the microcontroller’s I/O ports
provides a flexible means to ease layout concerns and save
board space. All members of the COP8 family provide the
ability to set, reset and test any individual bit in the data
memory address space, including memory-mapped I/O ports
and associated registers.
1.2.4 Register Set
Three memory-mapped pointers handle register indirect ad-
dressing and software stack pointer functions. The memory
data pointers allow the option of post-incrementing or post-
decrementing with the data movement instructions (LOAD/
EXCHANGE). And 15 memory-maped registers allow de-
signers to optimize the precise implementation of certain
specific instructions.
1.3 EMI REDUCTION
The COP8SGx5 family of devices incorporates circuitry that
guards against electromagnetic interference—an increasing
problem in today’s microcontroller board designs. National’s
patented EMI reduction technology offers low EMI clock
circuitry, gradual turn-on output drivers (GTOs) and internal
I
smoothing filters, to help circumvent many of the EMI
issues influencing embedded control designs. National has
achieved 15 dB–20 dB reduction in EMI transmissions when
designs have incorporated its patented EMI reducing cir-
cuitry.
1.4 PACKAGING/PIN EFFICIENCY
Real estate and board configuration considerations demand
maximum space and pin efficiency, particularly given today’s
high integration and small product form factors. Microcon-
troller users try to avoid using large packages to get the I/O
needed. Large packages take valuable board space and
increases device cost, two trade-offs that microcontroller
designs can ill afford.
The COP8 family offers a wide range of packages and do not
waste pins: up to 90.9% (or 40 pins in the 44-pin package)
are devoted to useful I/O.
C
www.national.com
3
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PDF描述 |
|---|---|
| COP8SGA040Q3 | LMH0046 HD/SD SDI Reclocker with Dual Differential Outputs; Package: TSSOP EXP PAD; No of Pins: 20 |
| COP8SGA040Q6 | 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART |
| COP8SGA040Q7 | 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART |
| COP8SGA040Q8 | 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART |
| COP8SGA040Q9 | 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART |
相关代理商/技术参数 |
参数描述 |
|---|---|
| COP8SGA040Q3 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART |
| COP8SGA040Q6 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART |
| COP8SGA040Q7 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART |
| COP8SGA040Q8 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART |
| COP8SGA040Q9 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART |
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