Hi folks,
I'm looking at using a PSoC MCU (current candidate is CYBLE-214009), to add modern connectivity and capabilities to a vintage hand-held computer.
To interface, I'm attempting to make the MCU emulate RAM/ROM (original RAM has 200ns access time), and read/write data, instructions, and status into/out of it over a range of addresses.
I think I'll be able to read the address bus with a status register and using an external pair of bus switchers to read the 16 bits in two 8-bit reads.
For the 8-bit data bus, I need a tristate interface so I can read or drive the data bus, depending on the value of the R/W signal from the handheld. It looks like older PSoC devices supported an EMIF device that would have been a ready-made solution for this, but, for some reason, this is not supported for PSoC 5.
What am currently thinking are 8-bit control and status registers, connected together through a bufoe per bit, and then to a bidirectional pin per bit. The bufoes will have their OEs connected together and to the R/W signal from its input pin.
First of all, will this work? Are there any special configuration settings required in the registers or in the bidirectional pins to make all this act like tristate?
Secondly, is there a way to make hooking these devices together easier and cleaner? Already with just one bit connected it looks pretty messy on the TopDesign view.
Thanks,
Paul
