Ask Helper2416 parallel port usage issues

arm9dzgc

Ask Helper2416 parallel port usage issues [Copy link]

Help: I use the DATA BUS of the Helper2416 core board (I drew the baseboard myself, this data bus is on the core board, but not on the Helper2416 development board) as the LCD driver interface, and the corresponding interface is as follows: Core board: LCD nCS2: CS nWR: WR nRD: RD ADDR2: RS (H data register operation, L command register operation) DATA0-DATA7: In the data line program, 0x10000000 is used as the read and write command address, and 0x10000004 is used as the data read and write address. It is found that during the debugging process, the command can be written to the LCD (as can be seen by the background changes of the LCD display, etc.), it should be said that CS, WR, DATA0-DATA7 are all correct, but the data cannot be written. Using an oscilloscope, it is found that ADDR2 has not changed and has always been L (corresponding to address 0x10000004, ADDR2 should be H). Please tell me what the reason is, is ADDR2 actually brought out on the core board?

arm9dzgc

It has been solved. When ADDR2 is used as the instruction and data selection of LCD, the address of read and write data is 0x10000008. It is mainly affected by the 2440 core board used before. When the previous core board used ADDR2 as the RS of LCD, the address of read and write data was 0x10000004. It may be that when the core board was designed, the address definition was different considering the number of data bits.

spacexplorer

Ok, it's solved. I haven't been here for a few days and didn't see the problem in time. Sorry!