I am using a 89C51RD2 development board running at 16MHz utilizing a memory mapped address/data bus design. I want to interface a Hitachi HD44780 2*16 LCD module and propose to use some addressed latches as the clock speed is too fast too interface the LCD directly to the bus.
I propose to use two Octal D-type latches (7HC574). One will connect to the LCD data pins, the other will interface to EN,RS,RW and an extra output to tri-state the above data pin latches when reading back busy flag or LCD ram.
In addition I would like to use an Octal transceiver (74HC245) to monitor the busy flag etc., (Though I could probably live without this in the design if I have to).
I think the control lines for the LCD might benefit from pull up resistors but am not sure about the data lines with this arrangement.I am open to any comments on my chip selection or my design proposal - be gentle though, I do not profess to be an experienced designer just always willing to learn.
I have previously used this LCD module directly to the port pins of the microcontroller but it leaves me very few available pins for other interfaces and since I have the memory map design available I figure I might as well utilize it.I did a forum search but most comments on pull ups and LCDs related to use with port P0.