Connect STM32 FSMC to LCM with 6800 interface

[diverger]

Posted on February 24, 2017 at 12:04

I want to use STM32 to drive a LCM with a KS0108 controller. Sadly, it has a 6800 interface. Fortunately, ST gives a document to guide me:

http://www.st.com/content/ccc/resource/technical/document/application_note/85/ad/ef/0f/a3/a6/49/9a/CD00201397.pdf/files/CD00201397.pdf/jcr:content/translations/en.CD00201397.pdf

 . In p. 12 it gives two methods:

But the

http://www.techtoys.com.hk/Displays/JHD12864J/ks0108.pdf

, states when write to LCD, the data is latched at the falling edge of ''E'':

 

Then, assuming we use the method 1 above, the pseudo-code should like:

lcd_addr = lcd_data;

gpio_E = LOW;

After the first clause, the /CS should goes to high, what's the state of the data bus, will it hold the data last output??? Or it will go to high impedance after /CS high? How can we make sure the LCM to latch the correct data?

For method 2, the situation should be similar.

Anyone ever tried ST's method?

#stm32 #6800 #lcd

[waclawek.jan]

Posted on February 25, 2017 at 11:43

IMO the FSMC in STM32 is not capable of true Motorola-style interface.

I'd manually bit-bang it, especially since there are only 512 bytes of memory in that LCD. With a bit of imagination, timer-triggered-DMA could be used for some degree of automation.

JW