Can I just connect my CPU (W65C02S) clock up to the 65C22

[Kellan]

I'm sorry if this is a noob question, but I personally can't find an answer other than maybe following wires on a C64 datasheet.
I'm trying to make a simple 65C02 breadboard computer with nothing more than the CPU, some RAM, and an EEPROM. I decided that instead of using AND gates and a decoder for a rough MMIO I'd use the 65C22. My question her is what do I do for the CLK pin on the 65C22? My current plan is to have a 1mhz clock running straight into the PH2I pin of the 65C02, but im wondering if I just run that same signal into the 65C22, or do I have to use a seperate clock? And if so at what frequency?

[Dr Jefyll]

Welcome, Kellan. Here in the Newbie section you have no worries, as noob questions are 100% allowed!

Kellan wrote:

My current plan is to have a 1mhz clock running straight into the PH2I pin of the 65C02, but im wondering if I just run that same signal into the 65C22, or do I have to use a seperate clock? And if so at what frequency?

If it's a modern WDC 65C02 (not an older chip such as those made by Rockwell) then the recommendation is to run the clock signal straight into the PH2I input (pin 37) of the 65C02, and also to the PH2I input on the 65C22. The clock signal also MUST be involved regarding either Chip Enable of Wrire Enable of the RAM.

These and many other issues are covered on this page of Garth Wilson's site: 6502 Primer: Building your own 6502 computer.

cheers
Jeff

[BigDumbDinosaur]

Kellan wrote:

I'm sorry if this is a noob question, but I personally can't find an answer other than maybe following wires on a C64 datasheet.
I'm trying to make a simple 65C02 breadboard computer with nothing more than the CPU, some RAM, and an EEPROM. I decided that instead of using AND gates and a decoder for a rough MMIO I'd use the 65C22. My question her is what do I do for the CLK pin on the 65C22? My current plan is to have a 1mhz clock running straight into the PH2I pin of the 65C02, but im wondering if I just run that same signal into the 65C22, or do I have to use a seperate clock? And if so at what frequency?

The Ø2 pin on the 65C22 should be connected to the same clock generator that is connected to the Ø2 (PH2I) pin on the 65C02.

[Kellan]

Thank you. That is exactly what I needed.

[GARTHWILSON]

Welcome.

I see two others posted while I was writing, but I'll finish anyway. Use the first diagram near the top of the "Circuit potpourri" page of the 6502 primer as a pattern. Heed the notes under that diagram too, especially about the clock source and distribution. Several other pages of the primer will be especially relevant too. The primer is intended to take you through all the necessary parts of building your own 6502 computer and getting it going, plus ideas of what can be done with it hardwarewise; so the sections are arranged in a logical order, and it's good to go through it in that order.