Another experimental CPU upgrade module for Z20X with the ZiLOG’s Z8L382 processor which is built around the 32-bit Z380 core. More information about Z8L382 and Z380 can be found on the website.

Z8L382 is the 3.3V low-power variant of the Z80382 chip. It works at up to 10 MHz clock, so the module implements its own clock generator. An additional challenge is that there is no internal ROM in the chip, one needs to be provided externally. This bring up a new challenge how that external memory will be programmed. Typically all processors that include an internal flash memory array provide options for in-circuit programming. With an external chip that is not possible, so I chose to use one in PLCC package instead of the traditional SMT-soldered options. Thus, the memory can be programmed by using an external flash programmer, and then installed into the socket on the module. The flash memory used here is SST39LF040-55-4C-NHE by Microchip. It is a 512K x8 memory. The recommended PLCC-32 socket is 8432-11B1-RK-TP manufactured by 3M.

Z8L382 also does not include a Real-Time Clock, and furthermore, has no I²C bus support, so an SPI version is being used here, instead.

Due to these additional components, the PCB for the module is a bit larger – 57.7 x 38.6mm (approximately 2.25” x 1.5”) 4-layer PCB that also accommodates several passive components (0805 size) the four 26-way dual row headers on the bottom side for connection with the main board.