Introduced in 1987, the Z280 was an advanced 16 bit microprocessor that was object code compatible with the popular Z80. The Z280 included memory management, peripherals, memory refresh logic, cache memory, wait state generators and a clock oscillator on the same die as the CPU itself. On-chip peripherals inclde 4x DMA channels, 3 counter / timers and a UART. It has a multiplexed address / data bus. Two different bus structures are supported by the Z280, an 8 bit data bus that uses Z80 control signals and a 16 bit data bus that uses the Z-Bus control signals as used by the Z8000 family of peripherals.