LCD interfacing with ARM cortex M0+ lpc845

Hi,

 

I'm trying to interface 8x2 lcd using parallel interfacing[4 bit mode], Display used - 8x2 lcd [PC 0802--A] ST7066U--Dot Matrix LCD Controller/Driver

Since I'm trying to interface using GPIO pins, not using I2C or SPI interface, and since no lcd drivers found for this particular MCU [LPC845],

I compared with lpc2148 MCU [lcd.c and lcd.h files], and have made the changes, but not able to write to the display.

And when checked the data/command signals in the oscilloscope, in data pins getting toggling pulse for D4-D6, in D7 i'm getting low pulse,

and high signals on command pins[RS,RW,EN].

Kindly suggest me the process of writing the char/string to the display varies for ARM mcu?as I'm referring lpc2148 libraries for LPC845 MCU .

 

Thank you