Oleg Sergeev wrote:
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hi,
by first quick look:
1) use one of A8...A15 lines for RS signal of LCD; it keeps P1.3 for another usage. Possible such method may be used for LITE (as I understand, it is R/W) signal as well - anyway the main control feature for LCD is EN strobe signal so you may set both RS and LITE before use strobe. Indeed, it requires some additional programming of P2.x bits.
2) use additional latch on port 0 and one extra pin for load A8...A15 in it. This way you may set high byte of memory address manually to this latch and then use MOVX @Ri,A for memory access. Such command keeps P2 value during external memory access and so P2 may be still used as output port for your purposes.
3) use MCU with more pins.
4) use CPLD as expander.

Regards,
Oleg

Hi Oleg,
If I use 1 pin of A8 - A15 for LCD then I will end up using less ram, As I have mentioned I need 64K RAM.

Please Suggest how can I use additional latch on port0 to save port pins.

MCU with more pins not aviable/too costly for this one of project.

CPLD too costly for one of project.

Rgds
Raj Shetgar