pfournier
Joined: 30 Sep 2003 Posts: 89
|
External Ram on an 18F8722 |
Posted: Thu Apr 30, 2009 1:13 pm |
|
|
I have a 18f8722 connected to ram and described in the
Microchip DS39646C-page 102,
FIGURE 7-2: 16-BIT WORD WRITE MODE EXAMPLE.
I also looked at Microchip's AN869, DS00869B
External Memory Interfacing Techniques for the PIC18F8XXX.
FIGURE 4: BASIC EXTERNAL MEMORY CONNECTION DIAGRAM
and
FIGURE 6: WORD WRITE MODE EXAMPLE
I set up like this:
Code: | #fuse EMCU, ABW16, AW16, WAIT |
I set MEMCON=0x02
I used:
Code: | write_external_memory command(0x20002, ptr, 2); |
Watching the signals using a logic analyzer, the address seems to be wrong in some sort of unpredictable way. Can anyone see something wrong in the setup? _________________ -Pete |
|