NEC V20 is a 16-bit CMOS microprocessor with 8-bit external data bus,
object-code and pin-compatible with Intel 8088.
The V20 runs at the same speed as the 8088, but it's slightly faster due
to internal improvements - dual internal 16-bit data bus,
faster effective address calculation, better loop counter/shift register
implementation, and some others. The V20 includes
Intel 8080 emulation mode, in which it can execute
all of the 8080 instructions. Native NEC V20 instruction set includes
all 8086/8088 instructions, new instructions from the 80186/80188 microprocessor,
and instructions unique to V20 - bit processing, packed BCD instructions and
special instructions for switching the processor to 8080 emulation mode and back.
The V20 is almost the same as the NEC V30 with the
exception that the V30 has 16-bit data bus.
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