Is there an equivalent mcu for the 16F648A in 18F series ??

[arunb]

Hi,

I need to replace the 18 pin 16F648A with a higher ROM and RAM version say 18F series, but with the same or slightly more pin count, is there any mcu that is best suited,...??

thanks
arunb

[Ttelmah]

This is what the Microchip device selector is for...
If you select 'search' from the '8bit processor' selection, you can put in criteria and get it to automatically find a chip.
I can't think of any in the 18pin package. The 18F1320, will match what you have in terms of ROM, and depending on what the code involves, may actually give you some extra space (the hardware multiplier saves quite a bit in some areas, but the greater number of registers, costs space for things like the interrupt handlers).
A little will depend on what features of the chip you actually need, but (for example), the 18F2455, is commonly in use at present for USB interfaces, and has all the same peripherals, plus the ECCP module, and the USB interface, with triple the ROM, and eight times the RAM. This though shifts you up to the 28pin package.

Best Wishes