How can I make a programmable latch 16/8 bits? Is there an example that gives me a headstart?

[Anonymous]

I want to make a comparator 16 bits wide,  i want to be able to store the value to compare to from the software.

When the 16 value on 16 inputs equals the stored value, a latch signal should be sent to a 8 bit wide latch that latches 8 inputs to a read-buffer.

The latch signal should also be readable by software to indicate a new 8 bit value is present.

Another option would be to have 16 inputs and 8 inputs latched on an external signal, so that they can be read by the software.

The intended usage would be investigating an 8 bit CPU, preferable in-circuit by probing the address and databus.

Would be nice if the latches could be read by means of interrupt which fills a buffer, in a sort of DMA way.

Is that possible with a PSoC5LP?

[Bob_Marlowe]

PSoC5 has digital comparator and status register components from which you can easily build the required latches you want.

Bob

[MotooTanaka · Accepted solution]

Hi,

This may not be the most elegant implementation,

but my trial seems to be doing what was asking for ...

The schematic

moto

[Anonymous]

Hi Motoo Tanaka, great thanks, that is exactly what I was looking, great starting point!