Hi,

I am trying to interface M68HC11E0 with an LM628/629 motion control chip to control a Pittman Motor. This is the first time I have used motion control chips and am having a hard time controlling them with the HC11. I am programming in C and using ICC11 as my compiler. If anyone has some basic C code that they could share with me as a starting point I would really appreciate it.

Thank you for your time,

Sincerely,

Devang Shah
[email protected]

 

One issue with these chips is that you must wait a millisecond or so between commands. If you blast them with reads at high speed, they will miss their internal interupts and lose counts.

Hope this helps,

Bill Sturm

 

Dear Bill,

Thank you for your message. I have tried unsuccessfully to employ your strategy. I was wondering if there is a problem with the timing, i.e. HC11 runs on a 2MHz clock while LM629 runs on an 8Mhz clock. What microcontrollers have you used to control the LM629? Maybe I could switch microcontrollers all together if you have any suggestions.

Thank you,

Devang

 

Sorry, that is all of the info that I know. I was
using an ISA card in an embedded DOS based PC. The card had C libraries for all of the interface details, but the timing issues were still up to my program to resolve.

Bill

 

I did a project with the LM828/629 many years ago. You have to be very careful with the timing signals (select, RD/WR, etc) with this chip. Signals must be properly synchronized with the clock(s). It works very well when the signals are gated correctly. Don't change processors... look at your timing diagrams.

Jack Eskew
Microsmith, Inc.
301 W. Deer Valley Road # 3
Phoenix, AZ 85027
V: 623-587-6473
F: 623-587-0612

 

<p>Dear Bill,

<p>I can't read the status byte correctly after hardware reset.

<p>1. My 8 bit microcontroller 8031 runs on a 11.05MHz clock while LM629 runs on an approximately 1.83Mhz clock. Can lm629 work?

<p>What microcontrollers have you used to control the LM629? Maybe I could switch microcontrollers all together if you have any suggestions.

<p>2. i pull CS, PS, and RD logic low. then read the status byte, but I can't get the correct data¡±84¡± or ¡°c4¡±,what's the problem?

<p>3. when the microcontroller read the status byte, how can it get the data? from which register? can you give me the program?
<pre>
My program:
0000H
AJMP MAIN
0030H
MAIN: CLR P2.4 ;pull the cs low logic
CLR P2.5 ;pull the ps low logic
MOV @R0,A ;read the status byte
NOP
END
</pre>
<p>Thank you,

<p>sophia

 

Hello,

Have you hold RST line low at least 8 LM629 clock periods?
At 8 MHz clock the internal reset routine takes some 1.5 ms, so you may expect to wait some 7 ms using a 1.8 MHz clock.

Hope this helps.
Best regards