MSX Assembly Page

Z80/R800/Z180/Z380 MPU Comparison Chart

Z80 R800 Z180 Z380
External Data Bus Width 8-bit 8-bit 8-bit 16/32-bit
Address Space 64k 64k 1Mb 16Mb Linear
Number of register sets 2 2 2 8 16-bit
Number of register planes 1 1 1 4
Static core no no yes yes
CPU Speed 3.57 7.14 33 18
Clocks/Inst. Min 4 1 3 2
Relative Performance 1 7 11 9 (33)

Note: ZiLOG themselves rate the Z380 with a relative performance of 33 because of the 32-bits extended instruction set and all the other added features. However, although it does deserve a slightly higher rating because of that, in practice this 33 is pretty over the top. I’ll just stick with the CPU speed / min. clockticks indication :).