Working with the ST6218

[mathias2]

Posted on November 25, 2003 at 01:37

Working with the ST6218

[mathias2]

Posted on November 07, 2003 at 06:01

Hello! I've got a couple of questions regarding the ST6218. I've been working with several other ST6-circuits, but now I have some problems.

First of all, my emulator doesn't emulate PB6 on pin 8 on the probe. I've made basic measurements to ensure that the probe isn't broke, but it seems to be OK. I haven't followed the signal up to the emulator via the flat cables though, maybe I should. The emulator is a new general purpose ST62GP-EMU2, and as far as I know it has been working at least for the ST6201 and ST6265. My second guess would be some error in the compiler, so I programmed a real circuit and made the same tests without problems. So it's definitely an emulator problem. My conclusion is that either my emulator is broke (I find it hard to believe right now) or that the emulator FPGA models doesn't emulate the circuit quite as well as planned. So, are there any developers out there working with the ST6218 using this emulator without problems? My second question regarding this circuit is the WINEE program Option byte for this circuit. The D5 bit is supposed to enable Port Pull-up according to the datasheet, but the program states Port Pull-up disable instead. Which is it?! And while we're at it, how should the Micro Configuration dialog for the emulator be set for the same functionality? I sure am confused about it. Please answer as soon as possible, any answers are appreciated. Thanks!

[mathias2]

Posted on November 07, 2003 at 07:18

Now I've also followed the signal up to the emulator. The signal follows an uninterrupted path from the DUT via the probe and flat cable to U54B pin 9 on the ST62GP-DBE. I won't go further than that. U54B is a M74HC14B Schmittrigger. As I've indicated before, I think this might be some problem with the FPGA model for ST6218, but I might be wrong.

My test code tries to toggle the pin when configured as an open-collector output, but when used as intended it should be configured as an input with pull-up and interrupt. None of these configurations work. I've written the test code to toggle bit 0-7 of PortB, even though only PB4-PB6 is available, to see if there has been some sort of mix-up with the PortB bit numbers. No such luck, though. I hope you can shed some light on this issue. Thanks!

[vikas2]

Posted on November 25, 2003 at 01:37

There is no problem on emulating PB6 pin using ST62GP-EMU2. I am able to toggle PB6 pin with ST62GP-EMU2. May be there could be any fault in your emulator.

In the DBE (Dedicated Board)of the emulator there are 6 ICs for Port B encircled in a block and in between these 6 IC ''PORT B'' is Written. I think any one of these IC is damaged. If it is so then problem can be resolved by replacing the IC with a correct one. D5 bit(PORT PULL UP) of Option Byte: In the datasheets it is written that “This bit must be set high to have pull-up input state at reset on the I/O port. When this bit is low, I/O ports are in input without pull-up (high impedance state at reset).� But in actual it is the PORT PULL UP DISABLE bit. Setting D5 bit will disable the port pull up and clearing this D5 bit will pull up the ports. Datasheet will soon be modified accordingly. Pull-up Option while Emulating: When you first time start the emulator, then there appears a window MCU NAME/OPTIONS-ST6218. You can pull up the port pins in this Window. You can also select Frequency, pull-up timer, pull-up NNI pin, Enable LVD , Enable Watchdog etc.