How does the enable pin(pin 6) of JHD12864E function?

[saur]

Can anyone tell me how does the enable pin(pin 6) of JHD12864E function?
I mean to ask...that whether it is just to enable the GLCD or whether its function is to latch data using a high to low or low to high transition...
Thank u in advance....
waiting for replies from all of u....

 

[FoxyRick]

Re: JHD12864E enable pin

From the datasheet, it's obvious. See page 8...

https://www.engineersgarage.com/sites/default/files/Graphics LCD JHD12864E Datasheet.pdf

When writing to the GLCD, data is latched in on the falling edge of E.

When reading from the GLCD, data is available after tD after the rising edge of E.

 

[papunblg]

Re: JHD12864E enable pin

One use :-----
There are 2 ways to send commands/data to LCD. --(1) Call a time delay before sending next data/command to an LCD (2) To monitor the busy flag before issuing a command / data to the LCD.

Note:- D7 bit of (command reg) LCD is busy flag .To check that flag you need to make R/S=1 and RS=0 and a low to high pulse for the E pin. After that D7 pin reflects the state of busy flag.

Suppose D7 is connected to P1.7.READY:

SETB P1.7 ;To make P1.7 input port
CLR P2.0 ;RS=0 to access command reg
SETB P2.1 ;R/W = 1 to read command Reg
BACK:

CLR P2.2 ;E=0 to provide low to high pulse
ACALL DELAY ; give some time(pulse time)
SETB P2.2 ; low to high pulse ends
JB P1.7,BACK ; stay till busy flag=0
RET


So that was an example:-

Pin 6 is the Enable pin. When this goes from low to high and then to low again the LCD reads pins 4,5 and 7-14.

 

[saur]

Re: JHD12864E enable pin

Thanks...
Ur replies were very useful....
thanks a lot....