COP8

National Semiconductor COP8
General information
Launched1988 (1988)
Common manufacturer
Performance
Max. CPU clock rate0 Hz to 2 MHz
Data width8 (RAM), 8 (ROM)
Address width8 (RAM), 15 (ROM)
Architecture and classification
ApplicationEmbedded
Instruction setCOP8
Number of instructions69
Physical specifications
Package
  • 20, 28, and 40-pin DIP; 16, 20, and 28 pin SOIC; 44-pin PLCC
History
PredecessorCOP400
Successornone

The National Semiconductor COP8 is an 8-bit CISC core microcontroller. COP8 is an enhancement to the earlier COP400 4-bit microcontroller family. COP8 main features are:

  • Large amount of I/O pins
  • Up to 32 KB of Flash memory/ROM for code and data
  • Very low EMI
  • Many integrated peripherals (meant as single chip design)
  • In-System Programming
  • Free assembler toolchain. Commercial C compilers available
  • Free Multitasking OS and TCP/IP stack
  • Peak of 2 million instructions per second

The COP8 has a basic instruction cycle time 1/10 of the clock frequency; a maximum 10 MHz clock will result in a maximum 1 MHz instruction execution rate. (The 10 MHz clock is used directly by some timer peripherals.) The maximum instruction execution rate is 1 cycle per byte, and most 1-byte instructions operate in one instruction cycle. Some, particularly branch instructions, take one or two cycles more. Some models include a clock doubler, and although they still accept a maximum 10 MHz input clock, they internally double it to a 20 MHz master clock which then results in a 2 MHz instruction execution rate.:7,32

The chip is a static logic design which can tolerate an arbitrarily slow clock;:10 most models include a second 32768 Hz quartz clock crystal oscillator which can be used for the CPU clock while the high-speed clock is disabled to save power.