I've been reading the datasheet for the Z80 PIO chip a lot in the last few weeks, and I still don't fully understand what it's supposed to do. Take this diagram, from the Z80 CPU datasheet: This is an example of how to use the Z80 CPU with the Z80 PIO and a ROM chip.

Figure 1. The Z80 computer. (Click to enlarge.) Source: Z80.info. The linked article and schematic are worth a read. Is there a standard way of achieving multiple PIOs being controlled by the Z80? Again, I have no expertise in this area but I imagine that every trick possible was used to get the best out of these devices.

Nov 9, 2017 · Great Z80 project goes on with I/O accesses, finding a way to bring 6522 to life every time the Z80 does an *I/O cycle. 6522's CLK2 pin is driven: We can easily substitute the Z80's "I/O Request" (IORQ) pin, which is the pin used by the Z80 to tell the I/O chip that it …

Feb 16, 2013 · Alternatively, you can replace the uart with a z80 pio chip to communicate with a modern parallel mode LCD character display. It won't really do graphics, but it's easy to use and your z80 can print things early on. A ps/2 keyboard will be rather simple to interface. But anyway, the z80 is a good choice for your project.

Yes I'm sure: Z80 can execute continuously NOOP, from the begin to the end, without need other than Power supply, CLOCK running, RESET High, WAIT High, HALT High, BUSREQ High, better if not directly applied to the Vcc, but with a resistor …

May 12, 2012 · The original Z80 was produced in the older NMOS technology, the Z84C00 is its CMOS version. The CMOS version is able to run at higher clock frequencies. The Z84C00xxxxx is the CPU, the Z84C20 is a PIO (Parallel I/O) device, and the Z80C30 a CTC (Counter/Timer Circuit). Nowadays all microcontrollers include functions like PIO and CTC on chip.

The address bus of the Z80 is 16-bits wide (bits A0 through A15), meaning it can address 65536 locations. The low 8 bits of the bus are bits A0-A7, which can address 256 locations. Each of the I/O ports connected to the Z80 has a corresponding address of 0-255 (256 total addresses). Only one port responds to a particular address.

Jul 18, 2019 · It can also mean 'Parallel I/O' where data is sent as a group of bits in parallel over several wires at once as opposed to serially over a single wire. One example of this is the Z80 PIO and SIO peripheral chips. The Z80 SIO sends and receives serial data on two dedicated pins, and has other I/O pins which are dedicated to control and status ...

Jan 18, 2018 · The software works (I tried it on my Z80 board which is almost identical to yours) but you should add a delay at startup to ensure that all peripherals are stable before the CPU accesses them. When using a simple RC timed reset generator the CPU may come out of reset before the 16C550, then the CPU will try to initialize the UART before it is ...

What exactly does the Z80 PIO do? I've been reading the datasheet for the Z80 PIO chip a lot in the last few weeks, and I still don't fully understand what it's supposed to do. Take this diagram, from the Z80 CPU datasheet: This is ...