Table of Contents for Programming Languages: a survey

Zilog Z80

"The Zilog Z80 was a software-compatible extension and enhancement of the Intel 8080"


8080 registers:


The new registers introduced with the Z80 are:

" There is no direct access to the alternate registers; instead, two special instructions, EX AF,AF' and EXX,[32] each toggles one of two multiplexer flip-flops. This enables fast context switches for interrupt service routines: EX AF, AF' may be used alone, for really simple and fast interrupt routines, or together with EXX to swap the whole BC, DE, HL set. This is still several times as fast as pushing the same registers on the stack. Slower, lower priority, or multi level interrupts normally use the stack to store registers, however. "

"No multiply instruction is available in the original Z80."