Your web browser may be object pascal handbook pdf. Your internet connection may be unreliable. This made them more suitable for battery-powered devices. MCS-251 family of binary compatible microcontrollers.
With one instruction, the 8051 can switch register banks versus the time consuming task of transferring the critical registers to the stack, or designated RAM locations. The main program then performs serial reads and writes simply by reading and writing 8-bit data to stacks. External RAM and ROM share the data and address buses. The original 8051 core ran at 12 clock cycles per machine cycle, with most instructions executing in one or two machine cycles. 8051 could thus execute 1 million one-cycle instructions per second or 500,000 two-cycle instructions per second. Enhanced 8051 cores are now commonly used which run at six, four, two, or even one clock per machine cycle, and have clock frequencies of up to 100 MHz, and are thus capable of an even greater number of instructions per second. Dallas and a few Atmel devices have single cycle cores.